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Sample records for solidified pb-10 wt

  1. Fabrication and tensile properties of rapidly solidified Cu-10wt. %Ni alloy. [Cu-10Ni

    Energy Technology Data Exchange (ETDEWEB)

    Baril, D; Angers, R; Baril, J [Dept. of Mining and Metallurgy, Laval Univ., Ste-Foy, Quebec (Canada)

    1992-10-15

    Cu-10wt.%Ni ribbons were produced by melt spinning and cut into small particles with a blade cutter mill. The powders were then hot consolidated to full density by hot pressing followed by hot extrusion. Tensile properties of the resulting pieces were measured. Cu-10wt.%Ni cast ingots were also hot extruded and mechanically tested to compare with the rapidly solidified alloy and to evaluate the possible benefits brought by the rapid solidification process.

  2. Hardness and microstructural characteristics of rapidly solidified Al-8-16 wt.%Si alloys

    International Nuclear Information System (INIS)

    Uzun, O.; Karaaslan, T.; Gogebakan, M.; Keskin, M.

    2004-01-01

    Al-Si alloys with nominal composition of Al-8 wt.%Si, Al-12 wt.%Si, and Al-16 wt.%Si were rapidly solidified by using melt-spinning technique to examine the influence of the cooling rate/conditions on microstructure and mechanical properties. The microstructures of the rapidly solidified ribbons and ingot samples were investigated by the optical microscopy, electron microscopy and X-ray diffraction (XRD) techniques. The results showed that the structures of all melt-spun ribbons were completely composed of finely dispersed α-Al and eutectic Si phase, and primary silicon was not observed. The XRD analysis indicated that the solubility of Si in the α-Al matrix was greatly increased with rapid solidification. Additionally, mechanical properties of both conventionally cast (ingot) and melt-spun ribbons were examined by using Vickers indenter for one applied load (0.098 N). The hardness values of the melt-spun ribbons were about three times higher than those of ingot counterparts. The high hardness of the rapidly solidified state can be attributed to the supersaturated solid solutions. Besides, hardness values with different applied loads were measured for melt-spun ribbons. The results indicated that Vickers hardness values (H v ) of the ribbons depended on the applied load. Applying the concept of Hays-Kendall, the load independent hardness values were calculated as 694.0, 982.8 and 1186.8 MN/m 2 for Al-8 wt.%Si, Al-12 wt.%Si and Al-16 wt.%Si, respectively

  3. Directionally Solidified Aluminum - 7 wt% Silicon Alloys: Comparison of Earth and International Space Station Processed Samples

    Science.gov (United States)

    Grugel, Richard N,; Tewari, Surendra; Rajamure, R. S.; Erdman, Robert; Poirier, David

    2012-01-01

    Primary dendrite arm spacings of Al-7 wt% Si alloy directionally solidified in low gravity environment of space (MICAST-6 and MICAST-7: Thermal gradient approx. 19 to 26 K/cm, Growth speeds varying from 5 to 50 microns/s show good agreement with the Hunt-Lu model. Primary dendrite trunk diameters of the ISS processed samples show a good fit with a simple analytical model based on Kirkwood s approach, proposed here. Natural convection, a) decreases primary dendrite arm spacing. b) appears to increase primary dendrite trunk diameter.

  4. Characterization of the Ni-45wt% Ti shape memory alloy rapidly solidified

    International Nuclear Information System (INIS)

    Anselmo, G.C.S.; Castro, W.B. de; Araujo, C.J. de

    2010-01-01

    One important challenge of microsystems design is the implementation of miniaturized actuation principles efficient at the micro-scale. Shape memory alloys (SMAs) have early on been considered as a potential solution to this problem as these materials offer attractive properties like a high-power to weight ratio, large deformation and the capability to be processed at the micro-scale. shape memory characteristics of Ni-45wt%Ti alloy ribbons prepared by melt spinning were investigated by means of differential scanning calorimetry and X-ray. In these experiments particular attention has been paid to change the velocity of cooling wheel from 30 to 50 m/s. Then the cooling rates of ribbons were controlled. The effect of this cooling rate on martensitic transformation behaviors and structure are discussed. (author)

  5. Macrosegregation During Re-melting and Holding of Directionally Solidified Al-7 wt.% Si Alloy in Microgravity

    Science.gov (United States)

    Lauer, M.; Ghods, M.; Angart, S. G.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2017-08-01

    As-cast aluminum-7 wt.% ailicon alloy sample rods were re-melted and directionally solidified on Earth which resulted in uniform dendritically aligned arrays. These arrays were then partially back-melted through an imposed, and constant, temperature gradient in the microgravity environment aboard the International Space Station. The mushy zones that developed in the seed crystals were held for different periods prior to initiating directional solidification. Upon return, examination of the initial mushy-zone regions exhibited significant macrosegregation in terms of a solute-depleted zone that increased as a function of the holding time. The silicon (solute) content in these regions was measured on prepared longitudinal sections by electron microprobe analysis as well as by determining the fraction eutectic on several transverse sections. The silicon content was found to increase up the temperature gradient resulting in significant silicon concentration immediately ahead of the mushy-zone tips. The measured macrosegregation agrees well with calculations from a mathematical model developed to simulate the re-melting and holding process. The results, due to processing in a microgravity environment where buoyancy and thermosolutal convection are minimized, serve as benchmark solidification data.

  6. Effect of cooling rate and Mg addition on the structural evaluation of rapidly solidified Al-20wt%Cu-12wt%Fe alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karaköse, Ercan, E-mail: ekarakose@karatekin.edu.tr [Çankırı Karatekin University, Faculty of Sciences, Department of Physics, 18100 Çankırı (Turkey); Çolak, Hakan [Çankırı Karatekin University, Faculty of Sciences, Department of Chemistry, 18100 Çankırı (Turkey)

    2016-11-15

    The present work examines the effect of Mg contents and cooling rate on the morphology and mechanical properties of Al{sub 20}Cu{sub 12}Fe quasicrystalline alloy. The microstructure of the alloys was analyzed by scanning electron microscopy and the phase composition was identified by X-ray diffractometry. The melting characteristics were studied by differential thermal analysis under an Ar atmosphere. The mechanical features of the melt-spun and conventionally solidified alloys were tested by tensile-strength test and Vickers micro-hardness test. It was found that the final microstructure of the Al{sub 20}Cu{sub 12}Fe samples mainly depends on the cooling rate and Mg contents, which suggests that different cooling rates and Mg contents produce different microstructures and properties. The average grain sizes of the melt spun samples were about 100–300 nm at 35 m/s. The nanosize, dispersed, different shaped quasicrystal particles possessed a remarkable effect to the mechanical characteristics of the rapidly solidified ribbons. The microhardness values of the melt spun samples were approximately 18% higher than those of the conventionally counterparts. - Highlights: •Quasicrystal-creating materials have high potential for applications. •Different shaped nanosize quasicrystal particles were observed. •The addition of Mg has an important impact on the mechanical properties. •H{sub V} values of the MS0, MS3 and MS5 samples at 35 m/s were 8.56, 8.66 and 8.80 GPa. •The volume fraction of IQC increases with increasing cooling rates.

  7. Characterization of the Ni-45wt% Ti shape memory alloy rapidly solidified; Caracterizacao da liga Ni-45wt%Ti com efeito de memoria de forma solidificadas rapidamente

    Energy Technology Data Exchange (ETDEWEB)

    Anselmo, G.C.S.; Castro, W.B. de; Araujo, C.J. de, E-mail: walman@dem.ufcg.edu.b [Universidade Federal de Campina Grande (UAEM/UFCG), PB (Brazil). Unidade Academica de Engenharia Mecanica

    2010-07-01

    One important challenge of microsystems design is the implementation of miniaturized actuation principles efficient at the micro-scale. Shape memory alloys (SMAs) have early on been considered as a potential solution to this problem as these materials offer attractive properties like a high-power to weight ratio, large deformation and the capability to be processed at the micro-scale. shape memory characteristics of Ni-45wt%Ti alloy ribbons prepared by melt spinning were investigated by means of differential scanning calorimetry and X-ray. In these experiments particular attention has been paid to change the velocity of cooling wheel from 30 to 50 m/s. Then the cooling rates of ribbons were controlled. The effect of this cooling rate on martensitic transformation behaviors and structure are discussed. (author)

  8. Influence of Thermal Parameters, Microstructure, and Morphology of Si on Machinability of an Al–7.0 wt.% Si Alloy Directionally Solidified

    Directory of Open Access Journals (Sweden)

    Cássio A. P. Silva

    2018-01-01

    Full Text Available This study aims to correlate the influence of thermal and microstructural parameters such as growth rate and cooling rate (VL and TR and secondary dendrite spacing (λ2, respectively, in the machining cutting temperature and tool wear on the necking process of the Al–7 wt.% Si alloy solidified in a horizontal directional device using a high-speed steel with a tungsten tool. The dependence of λ2 on VL and TR and dependence of the maximum cutting temperature and maximum flank wear on λ2 were determined by power experimental laws given by λ2 = constant (VL and TRn and TMAX, VBMAX = constant (λ2n, respectively. The maximum cutting temperature increased with increasing of λ2. The opposite occurred with the maximum flank wear. The role of Si alloying element on the aforementioned results has also been analyzed. A morphological change of Si along the solidified ingot length has been observed, that is, the morphology of Si in the eutectic matrix has indicated a transition from particles to fibers along the casting together with an increase of the particle diameters with the position from the metal/mold interface.

  9. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    Science.gov (United States)

    Liu, D. R.; Mangelinck-Noël, N.; Gandin, Ch-A.; Zimmermann, G.; Sturz, L.; Nguyen Thi, H.; Billia, B.

    2016-03-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement.

  10. CAFE simulation of columnar-to-equiaxed transition in Al-7wt%Si alloys directionally solidified under microgravity

    International Nuclear Information System (INIS)

    Liu, D R; Mangelinck-Noël, N; Thi, H Nguyen; Billia, B; Gandin, Ch-A; Zimmermann, G; Sturz, L

    2016-01-01

    A two-dimensional multi-scale cellular automaton - finite element (CAFE) model is used to simulate grain structure evolution and microsegregation formation during solidification of refined Al-7wt%Si alloys under microgravity. The CAFE simulations are first qualitatively compared with the benchmark experimental data under microgravity. Qualitative agreement is obtained for the position of columnar to equiaxed transition (CET) and the CET transition mode (sharp or progressive). Further comparisons of the distributions of grain elongation factor and equivalent diameter are conducted and reveal a fair quantitative agreement. (paper)

  11. Impact of beryllium additions on thermal and mechanical properties of conventionally solidified and melt-spun Al–4.5 wt.%Mn–x wt.%Be (x = 0, 1, 3, 5) alloys

    International Nuclear Information System (INIS)

    Öz, Turan; Karaköse, Ercan; Keskin, Mustafa

    2013-01-01

    Highlights: • Thermal and mechanical properties of Al–Mn–Be alloys were investigated. • IQC Al–Mn–Be alloys were synthesized by the CS and MS techniques. • The volume fraction of IQC increases continuously with Be content. • The melting points of the QC i-phase were determined between 652 °C and 675 °C. • The maximum H V and σ values were found to be 124 kg/mm 2 and 458 MPa with the addition of 5% Be. - Abstract: The influence of beryllium (Be) addition on the quasicrystal-forming ability, thermal and mechanical properties of Al–4.5 wt.%Mn–x wt.%Be (x = 0, 1, 3, 5) alloys was investigated in this study. Quasicrystalline Al–Mn–Be alloys were synthesized by the conventionally casting and melt spinning techniques. The microstructures of the samples were characterized by scanning electron microscopy (SEM) and the phase composition was identified by X-ray diffractometry (XRD). The phase transition during the solidification process was studied by differential scanning calorimetry (DSC) and differential thermal analysis (DTA) under an Ar atmosphere. The mechanical properties of the conventionally solidified (CS) and melt-spun (MS) samples were measured by a Vickers micro-hardness indenter and tensile-strength tests. The Al–4.5 wt.%Mn alloy has a hexagonal structure and minor dendritic icosahedral quasicrystalline phase (IQC) precipitates surrounded by an α-Al matrix. Addition of Be into the Al–4.5 wt.%Mn alloy generates intermetallic Be 4 AlMn and IQC phases with the extinction of the hexagonal phase, and the fraction of IQC increases continuously with the increase in Be content. A considerable improvement in microhardness and tensile strength values was observed due to the addition of Be in different percentages into the composition

  12. Correlation of Thermal and Microstructural Properties of an Al-0.60wt%Mg-0.25wt%Fe-0.05wt%Cu Alloy Unidirectionally Solidified

    Directory of Open Access Journals (Sweden)

    Pedro LAMARÃO

    2014-09-01

    Full Text Available This work aims to study the thermal, mechanical and microstructural properties of an Al-0.60 wt% Mg-0.25 wt% Fe- -0.05 wt% Cu alloy for application as an electrical conductor. The ingots were obtained by unidirectional horizontal casting, and were sectioned in specific positions to the production of test specimens destined to mechanical tests and microstructural characterization. As results, one can observe that it was possible to obtain experimental models of correlation between the average dimple diameters and thermal variables, demonstrating a trend on the formation of smaller fracture dimples where the cooling was more intense. As one can associate smaller dimples with greater ultimate tensile strength, it is important to understand this mechanism. DOI: http://dx.doi.org/10.5755/j01.ms.20.3.5015

  13. Radioactive substance solidifying device

    International Nuclear Information System (INIS)

    Sakoda, Kotaro.

    1979-01-01

    Purpose: To easily solidify radioactive substances adhering to the surfaces of solid wastes without scattering in the circumference by paints, and further to reduce surface contamination concentrations. Constitution: Solid wastes are placed on a hanging plate, and dipped in paints within a paint dipping treatment tank installed at the lower part of a treatment tank by means of a monorail hoist, and the surfaces of said solid wastes are coated with paints, thereby to solidify the radioactivity on the surfaces of the solid wastes. After dipping, the solid wastes are suspended up to a paint spraying tank to dry the paints. After drying, non-contaminated paints are atomized to apply through an atomizing tube onto the solid wastes. After drying the atomized paints, the solid wastes are carried outside the treatment tank by means of the monorail hoist. (Yoshino, Y.)

  14. Radioactive waste solidifying material

    International Nuclear Information System (INIS)

    Ono, Keiichi; Sakai, Etsuro.

    1989-01-01

    The solidifying material according to this invention comprises cement material, superfine powder, highly water reducing agent, Al-containing rapid curing material and coagulation controller. As the cement material, various kinds of quickly hardening, super quickly hardening and white portland cement, etc. are usually used. As the superfine powder, those having average grain size smaller by one order than that of the cement material are desirable and silica dusts, etc. by-produced upon preparing silicon, etc. are used. As the highly water reducing agent, surface active agents of high decomposing performance and comprising naphthalene sulfonate, etc. as the main ingredient are used. As the Al-containing rapidly curing material, calcium aluminate, etc. is used in an amount of less than 10 parts by weight based on 100 parts by weight of the powdery body. As the coagulation controller, boric acid etc. usually employed as a retarder is used. This can prevent dissolution or collaption of pellets and reduce the leaching of radioactive material. (T.M.)

  15. Radioactive liquid waste solidifying device

    International Nuclear Information System (INIS)

    Uchiyama, Yoshio.

    1987-01-01

    Purpose: To eliminate the requirement for discharge gas processing and avoid powder clogging in a facility suitable to the volume-reducing solidification of regenerated liquid wastes containing sodium sulfate. Constitution: Liquid wastes supplied to a liquid waste preheater are heated under a pressure higher than the atmospheric pressure at a level below the saturation temperature for that pressure. The heated liquid wastes are sprayed from a spray nozzle from the inside of an evaporator into the super-heated state and subjected to flash distillation. They are further heated to deposit and solidify the solidification components in the solidifying evaporation steams. The solidified powder is fallen downwardly and heated for removing water content. The recovered powder is vibrated so as not to be solidified and then reclaimed in a solidification storage vessel. Steams after flash distillation are separated into gas, liquid and solids by buffles. (Horiuchi, T.)

  16. The crystal structure of Kirkiite, Pb10Bi3As3S19

    DEFF Research Database (Denmark)

    Makovicky, Emil; Balic Zunic, Tonci; Karanovic, Ljiljana

    2006-01-01

    and chemical analysis resulted in comparable formulae, Pb10Bi2.16As3.84S19 and Pb10.08Bi2.55Sb0.13As2.91S19, respectively, which are close to the ideal formula Pb10Bi3As3S19. The crystal lattice shows a pseudohexagonal symmetry, which is the cause of common twinning in this mineral. The main twin-law has (20...... layers parallel to (083) of kirkiite; the slabs are unit-cell-twinned on (010) refl ection planes. The structure contains one split As position, and two additional sites that could accommodate both As and Bi. The As,Bi distribution over these two sites is determined by the trapezoidal distortion...... of the half-octahedral coordination environment inside the tightly bonded double layers of the PbS-SnS archetype slabs. Owing to the stoichiometry requirements in this structure, Bi must also substitute for 1/11 of the Pb sites. Bond-valence calculations and the volumes of coordination polyhedra show...

  17. Method of solidifying radioactive laundry wastes

    International Nuclear Information System (INIS)

    Yasumura, Keijiro

    1984-01-01

    Purpose: To enable to solidify radioactive laundry wastes containing non-ionic liquid detergents less solidifiable by plastic solidification process in liquid laundry wastes for cloths or the likes discharged from a nuclear power plant. Method: Radioactive laundry wastes are solidified by using plastic solidifying agent comprising, as a main ingredient, unsaturated polyester resins and methylmethacrylate monomers. The plastic solidifying agents usable herein include, for example, unsaturated polyester resins prepared by condensating maleic anhydride and phthalic anhydride with propylene glycol and incorporated with methylmethacrylate monomers. The mixing ratio of the methylmethacrylate monomers is preferably 30 % by weight based on the unsaturated polyester resins. (Aizawa, K.)

  18. Method of solidifying radioactive wastes

    International Nuclear Information System (INIS)

    Fukazawa, Tetsuo; Ootsuka, Masaharu; Uetake, Naoto; Ozawa, Yoshihiro.

    1984-01-01

    Purpose: To prepare radioactive solidified wastes excellent in strength, heat resistance, weather-proof, water resistance, dampproof and low-leaching property. Method: A hardening material reactive with alkali silicates to form less soluble salts is used as a hardener for alkali silicates which are solidification filler for the radioactive wastes, and mixed with cement as a water absorbent and water to solidify the radioactive wastes. The hardening agent includes, for example, CaCO 3 , Ca(ClO 4 ) 2 , CaSiF 6 and CaSiO 3 . Further, in order to reduce the water content in the wastes and reduce the gap ratio in the solidification products, the hardener adding rate, cement adding rate and water content are selected adequately. As the result, solidification products can be prepared with no deposition of easily soluble salts to the surface thereof, with extremely low leaching of radioactive nucleides. (Kamimura, M.)

  19. Method of solidifying powderous wastes

    International Nuclear Information System (INIS)

    Kakimoto, Akira; Miyake, Takashi; Sato, Shuichi; Inagaki, Yuzo.

    1985-01-01

    Purpose: To improve the properties of solidification products, in the case of solidifying powderous wastes with thermosetting resins. Method. A solvent for the solution of the thermosetting resin is admixed with the powderous wastes into a paste-like form prior to adding the resin to the wastes, which are then mixed with the resin solution. As the result, those solidification products having the specific gravity and the compression strength more excellent than those of the conventional ones, and much higher than the reference values can be obtained. (Kamimura, M.)

  20. Effective hydrogen diffusion coefficient for solidifying aluminium alloys

    International Nuclear Information System (INIS)

    Felberbaum, M.; Landry-Desy, E.; Weber, L.; Rappaz, M.

    2011-01-01

    An effective hydrogen diffusion coefficient has been calculated for two solidifying Al - 4.5 wt.% Cu and Al - 10 wt.% Cu alloys as a function of the volume fraction of solid. For this purpose, in situ X-ray tomography was performed on these alloys. For each volume fraction of solid between 0.6 and 0.9, a representative volume element of the microstructure was extracted. Solid and liquid voxels were assimilated to solid and liquid nodes in order to solve the hydrogen diffusion equation based on the chemical potential and using a finite volume formulation. An effective hydrogen diffusion coefficient based on the volume fraction of solid only could be deduced from the results of the numerical model at steady state. The results are compared with various effective medium theories.

  1. Microstructure and orientation evolution in unidirectional solidified Al–Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhongwei, E-mail: chzw@nwpu.edu.cn; Wang, Enyuan; Hao, Xiaolei

    2016-06-14

    Morphological instability and growth orientation evolution during unidirectional solidification of Al–Zn alloys with different pulling speeds were investigated by X-ray diffraction (XRD) and electron back-scatter diffraction (EBSD) in scanning electron microscope (SEM). The experimental results show that, as the pulling speed increases, the primary dendrite spacing becomes smaller gradually and dendrite trunks incline to the heat flow direction perfectly in unidirectional solidified Al–9.8 wt%Zn and Al–89 wt%Zn alloys. However, regardless of the pulling speed in unidirectional solidified Al–Zn alloys under fixed thermal gradient, the regular dendrites with <100> directions of primary trunks and secondary arms in 9.8 wt% Zn composition are replaced by <110> dendrites of primary trunks and secondary arms in 89 wt% Zn composition. In unidirectional solidified Al–32 wt% Zn alloy, cellular, fractal seaweed, and stabilized seaweed structures were observed at high pulling speeds. At a high pulling speed of 1000 µm/s, seaweed structures transform to the columnar dendrites with <110> trunks and <100> arms. The above orientation evolution can be attributed to low anisotropy of solid-liquid interface energy and the seaweed structure is responsible for isotropy of {111} planes.

  2. Evaluating Primary Dendrite Trunk Diameters in Directionally Solidified Al-Si Alloys

    Science.gov (United States)

    Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2014-01-01

    The primary dendrite trunk diameters of Al-Si alloys that were directionally solidified over a range of processing conditions have been measured. These data are analyzed with a model based primarily on an assessment of secondary dendrite arm dissolution in the mushy zone. Good fit with the experimental data is seen and it is suggested that the primary dendrite trunk diameter is a useful metric that correlates well with the actual solidification processing parameters. These results are placed in context with the limited results from the aluminium - 7 wt. % silicon samples directionally solidified aboard the International Space Station as part of the MICAST project.

  3. Solidifying processing device for radioactive waste

    International Nuclear Information System (INIS)

    Sueto, Kumiko; Toyohara, Naomi; Tomita, Toshihide; Sato, Tatsuaki

    1990-01-01

    The present invention concerns a solidifying device for radioactive wastes. Solidifying materials and mixing water are mixed by a mixer and then charged as solidifying and filling materials to a wastes processing container containing wastes. Then, cleaning water is sent from a cleaning water hopper to a mixer to remove the solidifying and filling materials deposited in the mixer. The cleaning liquid wastes are sent to a separator to separate aggregate components from cleaning water components. Then, the cleaning water components are sent to the cleaning water hopper and then mixed with dispersing materials and water, to be used again as the mixing water upon next solidifying operation. On the other hand, the aggregate components are sent to a processing mechanism as radioactive wastes. With such procedures, since the discharged wastes are only composed of the aggregates components, and the amount of the wastes are reduced, facilities and labors for the processing of cleaning liquid wastes can be decreased. (I.N.)

  4. Method of solidifying radioactive waste

    International Nuclear Information System (INIS)

    Hasegawa, Akira; Mihara, Shigeru; Yamashita, Koji; Sauda, Kenzo.

    1988-01-01

    Purpose: To obtain satisfactory plastic solidification products rapidly and more conveniently from radioactive wastes. Method: liquid wastes contain, in addition to sodium sulfate as the main ingredient, nitrates hindering the polymerizing curing reactions and various other unknown ingredients, while spent resins contain residual cationic exchange groups hindering the polymerizing reaction. Generally, as the acid value of unsaturated liquid polyester resins is lower, the number of terminal alkyd resins is small, formation of nitrates is reduced and the polymerizing curing reaction is taken place more smoothly. In view of the above, radioactive wastes obtained by dry powderization or dehydration of radioactive liquid wastes or spent resins are polymerized with unsaturated liquid polyester resins with the acid value of less than 13 to obtain plastic solidification. Thus, if the radioactive wastes contain a great amount of polymerization hindering material such as NaNO 2 , they can be solidified rapidly and conveniently with no requirement for pre-treatment. (Kamimura, Y.)

  5. Method of solidifying radioactive wastes

    International Nuclear Information System (INIS)

    Maeda, Masahiko; Kira, Satoshi; Watanabe, Naotoshi; Nagaoka, Takeshi; Akane, Junta.

    1982-01-01

    Purpose: To obtain solidification products of radioactive wastes having sufficient monoaxial compression strength and excellent in water durability upon ocean disposal of the wastes. Method: Solidification products having sufficient strength and filled with a great amount of radioactive wastes are obtained by filling and solidifying 100 parts by weight of chlorinated polyethylene resin and 100 - 500 parts by weight of particular or powderous spent ion exchange resin as radioactive wastes. The chlorinated polyethylene resin preferably used herein is prepared by chlorinating powderous or particulate polyethylene resin in an aqueous suspending medium or by chlorinating polyethylene resin dissolved in an organic solvent capable of dissolving the polyethylene resin, and it is crystalline or non-crystalline chlorinated polyethylene resin comprising 20 - 50% by weight of chlorine, non-crystalline resin with 25 - 40% by weight of chlorine being particularly preferred. (Horiuchi, T.)

  6. Microstructure of rapidly solidified materials

    Science.gov (United States)

    Jones, H.

    1984-07-01

    The basic features of rapidly solidified microstructures are described and differences arising from alternative processing strategies are discussed. The possibility of achieving substantial undercooling prior to solidification in processes such as quench atomization and chill block melt spinning can give rise to striking microstructural transitions even when external heat extraction is nominally Newtonian. The increased opportunity in laser and electron beam surface melting for epitaxial growth on the parent solid at an accelerating rate, however, does not exclude the formation of nonequilibrium phases since the required undercooling can be locally attained at the solidification front which is itself advancing at a sufficiently high velocity. The effects of fluid flow indicated particularly in melt spinning and surface melting are additional to the transformational and heat flow considerations that form the present basis for interpretation of such microstructural effects.

  7. Primary Dendrite Arm Spacings in Al-7Si Alloy Directionally Solidified on the International Space Station

    Science.gov (United States)

    Angart, Samuel; Lauer, Mark; Poirier, David; Tewari, Surendra; Rajamure, Ravi; Grugel, Richard

    2015-01-01

    Samples from directionally solidified Al- 7 wt. % Si have been analyzed for primary dendrite arm spacing (lambda) and radial macrosegregation. The alloy was directionally solidified (DS) aboard the ISS to determine the effect of mitigating convection on lambda and macrosegregation. Samples from terrestrial DS-experiments thermal histories are discussed for comparison. In some experiments, lambda was measured in microstructures that developed during the transition from one speed to another. To represent DS in the presence of no convection, the Hunt-Lu model was used to represent diffusion controlled growth under steady-state conditions. By sectioning cross-sections throughout the entire length of a solidified sample, lambda was measured and calculated using the model. During steady-state, there was reasonable agreement between the measured and calculated lambda's in the space-grown samples. In terrestrial samples, the differences between measured and calculated lambda's indicated that the dendritic growth was influenced by convection.

  8. Method of solidifying radioactive solid wastes

    International Nuclear Information System (INIS)

    Fukazawa, Tetsuo; Kawamura, Fumio; Kikuchi, Makoto.

    1984-01-01

    Purpose: To obtain solidification products of radioactive wastes satisfactorily and safely with no destruction even under a high pressure atmosphere by preventing the stress concentration by considering the relationships of the elastic module between the solidifying material and radioactive solid wastes. Method: Solidification products of radioactive wastes with safety and securing an aimed safety ratio are produced by conditioning the modules of elasticity of the solidifying material equal to or less than that of the radioactive wastes in a case where the elastic module of radioactive solid wastes to be solidified is smaller than that of the solidifying material (the elastic module of wastes having the minimum elastic module among various wastes). The method of decreasing the elastic module of the solidifying material usable herein includes the use of such a resin having a long distance between cross-linking points of a polymer in the case of plastic solidifying materials, and addition of rubber-like binders in the case of cement or like other inorganic solidifying materials. (Yoshihara, H.)

  9. Liquid wastes concentrating and solidifying device

    International Nuclear Information System (INIS)

    Kamiyoshi, Hideki; Ninokata, Yoshihide.

    1985-01-01

    Purpose: To provide a device for concentrating to solidify radioactive liquid wastes at large solidifying speed and with high decontaminating coefficient, without requirement for automatic control. Constitution: An asphalt solidifying device is disposed below a centrifugal thin film drier, and powder resulted from the drier is directly solidified with asphalt by utilizing the rotation of the drier for the mixing operation in the asphalt vessel. If abnormality should occur in the operation of the drier, resulting liquid wastes can be received and solidified in the asphalt vessel. The liquid wastes are heated to dry in a vessel main body having the heating surface at the circumferential surface. The vessel main body provided with a nozzle for supplying liquid to be treated disposed slantwise at the upper portion of the heating face, scrapers which rotate and slidingly contact the heating face and nozzles which jet out chemicals to the heating face behind the scrapers. Below the vessel main body, are disposed a funnel-like hopper for receiving falling scales, rotary vanes, and the likes by which the scales are introduced into the asphalt solidifying vessel. (Moriyama, K.)

  10. Method of solidifying radioactive wastes with plastics

    International Nuclear Information System (INIS)

    Matsuura, Hiroyuki; Yasumura, Keijiro; Minami, Yuji; Tomita, Toshihide

    1980-01-01

    Purpose: To prevent solidification of solidifying agents in the mixer by conducting the mixing process for the solidifying agents and the radioactive wastes at a temperature below the initiation point for the solidification of the agents thereby separating the mixing process from the solidification-integration process. Method: Catalyst such as cobalt naphthenate is charged into an unsaturated polyester resin in a mixer previously cooled, for example, to -10 0 C. They are well mixed with radioactive wastes and the mixture in the mixer is charged in a radioactive waste storage container. The temperature of the mixture, although kept at a low temperature initially, gradually increases to an ambient temperature whereby curing reaction is promoted and the reaction is completed about one day after to provide firm plastic solidification products. This can prevent the solidification of the solidifying agents in the mixer to thereby improve the circumstance's safety. (Kawakami, Y.)

  11. Rapidly solidified aluminium for optical applications

    NARCIS (Netherlands)

    Gubbels, G.P.H.; Venrooy, B.W.H. van; Bosch, A.J.; Senden, R.

    2008-01-01

    This paper present the results of a diamond turning study of a rapidly solidified aluminium 6061 alloy grade, known as RSA6061. It is shown that this small grain material can be diamond turned to smaller roughness values than standard AA6061 aluminium grades. Also, the results are nearly as good as

  12. Method for solidifying powdery radioactive wastes

    International Nuclear Information System (INIS)

    Yasumura, Keijiro; Matsuura, Hiroyuki; Tomita, Toshihide.

    1978-01-01

    Purpose: To solidify powdery radioactive wastes through polymerization in a vessel at a high impregnation speed with no cloggings in pipes. Method: A drum can is lined with an inner liner layer of a predetermined thickness made of inflammable material such as glass fiber. A plurality of pipes for supplying liquid plastic monomer are provided in adjacent to the upper end face of the inflammable material or inserted between the vessel and the inflammable material. Then powdery radioactive wastes are filled in the vessel and the liquid plastic monomer dissolving therein a polymerization initiator is supplied through the pipes. The liquid plastic monomer impregnates through the inflammable material layer into the radioactive wastes and the plastic monomer is polymerized by the aid of the polymerization initiator after a predetermined of time to produce solidified plastic products of radioactive wastes. (Seki, T.)

  13. Leaching behavior of solidified plastics radioactive wastes

    International Nuclear Information System (INIS)

    Yook, Chong Chul; Lee, Byung Hun; Jae, Won Mok; Kim, Kyung Eung

    1986-01-01

    It is highly needed to develope the solidification process to dispose safely the radioactive wastes increasing with the growth of the nuclear industry. The leaching mechanisms of the solidified plastic wastes were investigated and the leaching rates of the plastic wastes were also measured among the many solidification processes. In addition, the transport equation based on the diffusion or the diffusion-dissolution was compared with the empirical equation derived from the experimental data by graphical method. Consequently, leaching process of the solidified plastic wastes is quite well agreed with the mass transport theory, but it may be difficult to simulate leaching process by diffusion dissolution mechanism. But the theoretical equation could be applicable to the cumulative amount of radionuclides leached form the plastic wastes disposed into the environment. (Author)

  14. Characterization of aluminium alloys rapidly solidified

    International Nuclear Information System (INIS)

    Monteiro, W.A.

    1988-01-01

    This paper discussed the investigation of the microstructural and mechanical properties of the aluminium alloys (3003; 7050; Al-9% Mg) rapidly solidified by melt spinning process (cooling rate 10 4 - 10 6 K/s). The rapidly solidification process of the studied aluminium alloys brought a microcrystallinity, a minimum presence of coarse precipitation and, also, better mechanical properties of them comparing to the same alloys using ingot process. (author) [pt

  15. A study on the microstructural characteristics of rapidly solidified Al-Fe alloys(I)

    International Nuclear Information System (INIS)

    Kim, D.H.; Lee, H.I.

    1991-01-01

    Solidification microstructures and phases in rapidly solidified Al-5, 10wt% Fe alloys have been investigated by TEM bright field and dark field imaging techniques and electron and x-ray diffraction techniques. Rapid solidification of Al-5, 10wt%Fe alloys produces various metastable and stable phases, such as Al m Fe, Al 6 Fe and Al 13 Fe 4 . In addition to these phases, clusters of randomly oriented few nm scale particles exist in the form of fine cellular network with α-Al or primary spherical particles. Solidification microstructures of the rapidly solidified Al-5, 10wt%Fe alloys consist of various combination of primary phases such as Al 13 Fe 4 , Al m Fe and cluster of nm scale particles, and cellular/dendritic structures such as fine cellular network structure of nm scale particle clusters and α-Al and cellular structure of Al m Fe and α-Al, depending upon alloy compositions and local cooling rates. (Author)

  16. Effect of solidification parameters on mechanical properties of directionally solidified Al-Rich Al-Cu alloys

    Science.gov (United States)

    Çadırlı, Emin

    2013-05-01

    Al(100-x)-Cux alloys (x=3 wt%, 6 wt%, 15 wt%, 24 wt% and 33 wt%) were prepared using metals of 99.99% high purity in vacuum atmosphere. These alloys were directionally solidified under steady-state conditions by using a Bridgman-type directional solidification furnace. Solidification parameters (G, V and ), microstructure parameters (λ1, λ2 and λE) and mechanical properties (HV, σ) of the Al-Cu alloys were measured. Microstructure parameters were expressed as functions of solidification parameters by using a linear regression analysis. The dependency of HV, σ on the cooling rate, microstructure parameters and composition were determined. According to experimental results, the microhardness and ultimate tensile strength of the solidified samples was increased by increasing the cooling rate and Cu content, but decreased with increasing microstructure parameters. The microscopic fracture surfaces of the different samples were observed using scanning electron microscopy. Fractographic analysis of the tensile fracture surfaces showed that the type of fracture significantly changed from ductile to brittle depending on the composition.

  17. Cation distributions on rapidly solidified cobalt ferrite

    Science.gov (United States)

    De Guire, Mark R.; Kalonji, Gretchen; O'Handley, Robert C.

    1990-01-01

    The cation distributions in two rapidly solidified cobalt ferrites have been determined using Moessbauer spectroscopy at 4.2 K in an 8-T magnetic field. The samples were obtained by gas atomization of a Co0-Fe2O3-P2O5 melt. The degree of cation disorder in both cases was greater than is obtainable by cooling unmelted cobalt ferrite. The more rapidly cooled sample exhibited a smaller departure from the equilibrium cation distribution than did the more slowly cooled sample. This result is explained on the basis of two competing effects of rapid solidification: high cooling rate of the solid, and large undercooling.

  18. Radial macrosegregation and dendrite clustering in directionally solidified Al-7Si and Al-19Cu alloys

    Science.gov (United States)

    Ghods, M.; Johnson, L.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2016-05-01

    Hypoeutectic Al-7 wt% Si and Al-19 wt% Cu alloys were directionally solidified upward in a Bridgman furnace through a range of constant growth speeds and thermal gradients. Though processing is thermo-solutally stable, flow initiated by gravity-independent advection at, slightly leading, central dendrites moves rejected solute out ahead and across the advancing interface. Here any lagging dendrites are further suppressed which promotes a curved solid-liquid interface and the eventual dendrite "clustering" seen in transverse sections (dendrite "steepling" in longitudinal orientations) as well as extensive radial macrosegregation. Both aluminum alloys showed considerable macrosegregation at the low growth speeds (10 and 30 μm s-1) but not at higher speed (72 μm s-1). Distribution of the fraction eutectic-constituent on transverse sections was determined in order to quantitatively describe radial macrosegregation. The convective mechanisms leading to dendrite-steepling were elucidated with numerical simulations, and their results compared with the experimental observations.

  19. Site Simulation of Solidified Peat: Lab Monitoring

    Science.gov (United States)

    Durahim, N. H. Ab; Rahman, J. Abd; Tajuddin, S. F. Mohd; Mohamed, R. M. S. R.; Al-Gheethi, A. A.; Kassim, A. H. Mohd

    2018-04-01

    In the present research, the solidified peat on site simulation is conducted to obtain soil leaching from soil column study. Few raw materials used in testing such as Ordinary Portland Cement (OPC), Fly ash (FA) and bottom ash (BA) which containing in solidified peat (SP), fertilizer (F), and rainwater (RW) are also admixed in soil column in order to assess their effects. This research was conducted in two conditions which dry and wet condition. Distilled water used to represent rainfall during flushing process while rainwater used to gain leaching during dry and wet condition. The first testing made after leaching process done was Moisture Content (MC). Secondly, Unconfined Compressive Strength (UCS) will be conducted on SP to know the ability of SP strength. These MC and UCS were made before and after SP were applied in soil column. Hence, the both results were compared to see the reliability occur on SP. All leachate samples were tested using Absorption Atomic Spectroscopy (AAS), Ion Chromatography (IC) and Inductively-Coupled Plasma Spectrophotometry (ICP-MS) testing to know the anion and cation present in it.

  20. Method and apparatus for solidifying radioactive waste

    International Nuclear Information System (INIS)

    Kadota, Hiroko; Kikuchi, Makoto; Tsuchiya, Hiroyuki; Tamada, Shin.

    1989-01-01

    The present invention concerns a method of solidifying radioactive wastes that generate heat with water curing solidifying material and the object there of is suppress the effect of heat generation of the wastes given on the solidification material. That is, it is a feature of the invention to inject water content contained in the water curable solidification material in the form of ice into the wastes. Thus, since the water content in the water curable solidification material is ice, the solidification products can be obtained by way of the following three steps: (1) ice is dissolved into water, (2) solid content of the solidification material is dissolved into water, and(3) curing reaction of the solidification material is started. Acccordingly, since the heat generated from the wastes contributes as heat of reaction when ice is dissolved into water till the solidification material has been completely filled, promotion for the curing reaction causing problems so far can be suppressed to enable easy filling. Then, after the completion of the filling of the solidification material, the heat of the wastes has an effect of promoting the second and the third steps described above to accelerate the curing reaction. (K.M.)

  1. Method and device for solidifying radioactive waste

    International Nuclear Information System (INIS)

    Hayashi, Tadamasa.

    1981-01-01

    Purpose: To solidify radioactive waste without producing radioactive dusts by always heating and evaporating the water from liquid radioactive waste in a mixture of liquid plastic and exhausting the molten mixture of the waste residue and the plastic material. Constitution: Liquid plastic material in a tank cooled to prevent polymerization or changes of its properties is continuously supplied to the top of a heating and mixing evaporator by a constant supply pump. After the heat transfer surface of the evaporator is covered with the plastic material, radioactive waste in the tank is supplied to the evaporator via the constant supply pump. The waste is abruptly mixed with the plastic material by an agitating rotor, heated by a heater, and the evaporated water is fed to a condenser. An anhydrous molten mixture is continuously exhausted from the bottom of the evaporator into a mixture cooler, a polymerizing agent and catalyst are introduced thereinto from a polymerizing agent tank and a catalyst tank, inhibitor is introduced thereinto from a polymerization inhibitor tank as required, and is filled with the mixture a solidifying container while it is cooled for its polymerization and solidification. (Yoshino, Y.)

  2. Method of solidifying radioactive waste by plastics

    International Nuclear Information System (INIS)

    Yasumura, Keijiro; Tomita, Toshihide.

    1976-01-01

    Purpose: To prevent leakage of radioactivity by providing corrosion-resistant layer on the inner surface of a waste container for radioactive waste. Constitution: The inner periphery and bottom of a drum can is lined with an non-flammable cloth of such material as asbestos. This drum is filled with a radioactive waste in the form of powder or pellets. Then, a mixture of a liquid plastic monomer and a polymerization starting agent is poured at a normal temperature, and the surface is covered with a non-flammable cloth. The plastic monomer and radioactive waste are permitted to impregnate the non-flammable cloth and are solidified there. Thus, even if the drum can is corroded at the sea bottom after disposal it in the ocean, it is possible to prevent the waste from permeating into the outer sea water because of the presence of the plastic layer on the inside. Styrene is used as the monomer. (Aizawa, K.)

  3. A process for solidifying radioactive liquid waste

    International Nuclear Information System (INIS)

    Mergan, L.M.; Cordier, J.-P.

    1981-01-01

    In a process for solidifying radioactive liquid waste, its pH is adjusted, solids precipitated and then it is concentrated to about 50% solids content using a thin film evaporator, the concentrate then being dried to powder in a heated mixer. The mixer has a heated wall and working means, e.g. a rotor and helical screw, to shear the dried concentrate from the internal walls, subdivide it into a dry particulate powder, and advance the powder to the mixer outlet. The dried particles are then encapsulated in a suitable matrix. Vapour from the mixer and evaporator is condensed and recycled after any particles have been removed from it. The mixer may both dry the concentrate and mix the dry particles with the encapsulating matrix, and possibly, part of the mixer may be used for pH adjustment and precipitation. (author)

  4. Method of solidifying radioactive liquid wastes

    International Nuclear Information System (INIS)

    Uetake, Naoto; Kawamura, Fumio; Kikuchi, Makoto; Fukazawa, Tetsuo.

    1983-01-01

    Purpose: To enable to confine the volatiling ingredients such as cesium in liquid wastes safely in glass solidification products while suppressing the volatilization thereof. Method: Acid salt of tetravalent metal such as titanium phosphate has an intense selective adsorption property to cesium. So liquid wastes stored in a high level liquid wastes tank is mixed with titanium phosphate gels stored in an adsorbent tank, then supplied to a mixer and mixed with a sodium silicate solution stored in a sodium silicate storage tank and boric acid stored in an additive tank, into gel-like state. The gel-like material thus formed is supplied to a drier. After being dried at a temperature of 200sup(o)C - 300sup(o)C, the material is melted under heating at a temperature of 1000sup(o)C - 1100sup(o)C, and then cooled to solidify. (Horiuchi, T.)

  5. Interconnection of thermal parameters, microstructure and mechanical properties in directionally solidified Sn–Sb lead-free solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Marcelino; Costa, Thiago [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil); Rocha, Otávio [Federal Institute of Education, Science and Technology of Pará — IFPA, 66093-020 Belém, PA (Brazil); Spinelli, José E. [Department of Materials Engineering, Federal University of São Carlos — UFSCar, 13565-905 São Carlos, SP (Brazil); Cheung, Noé, E-mail: cheung@fem.unicamp.br [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil); Garcia, Amauri [Department of Manufacturing and Materials Engineering, University of Campinas — UNICAMP, 13083-860 Campinas, SP (Brazil)

    2015-08-15

    Considerable effort is being made to develop lead-free solders for assembling in environmental-conscious electronics, due to the inherent toxicity of Pb. The search for substitute alloys of Pb–Sn solders has increased in order to comply with different soldering purposes. The solder must not only meet the expected levels of electrical performance but may also have appropriate mechanical strength, with the absence of cracks in the solder joints. The Sn–Sb alloy system has a range of compositions that can be potentially included in the class of high temperature solders. This study aims to establish interrelations of solidification thermal parameters, microstructure and mechanical properties of Sn–Sb alloys (2 wt.%Sb and 5.5 wt.%Sb) samples, which were directionally solidified under cooling rates similar to those of reflow procedures in industrial practice. A complete high-cooling rate cellular growth is shown to be associated with the Sn–2.0 wt.%Sb alloy and a reverse dendrite-to-cell transition is observed for the Sn–5.5 wt.%Sb alloy. Strength and ductility of the Sn–2.0 wt.%Sb alloy are shown not to be affected by the cellular spacing. On the other hand, a considerable variation in these properties is associated with the cellular region of the Sn–5.5 wt.%Sb alloy casting. - Graphical abstract: Display Omitted - Highlights: • The microstructure of the Sn–2 wt.%Sb alloy is characterized by high-cooling rates cells. • Reverse dendrite > cell transition occurs for Sn–5.5 wt.%Sb alloy: cells prevail for cooling rates > 1.2 K/s. • Sn–5.5 wt.%Sb alloy: the dendritic region occurs for cooling rates < 0.9 K/s. • Sn–5.5 wt.%Sb alloy: tensile properties are improved with decreasing cellular spacing.

  6. Modification effect of Ni-38 wt.%Si on Al-12 wt.%Si alloy

    International Nuclear Information System (INIS)

    Wu Yuying; Liu Xiangfa; Jiang Binggang; Huang Chuanzhen

    2009-01-01

    Modification effect of Ni-38 wt.%Si on the Al-12 wt.%Si alloy has been studied by differential scanning calorimeter, torsional oscillation viscometer and liquid X-ray diffraction experiments. It is found that there is a modification effect of Ni-38 wt.%Si on Al-12 wt.%Si alloy, i.e. primary Si can precipitate in the microstructure of Al-12 wt.%Si alloy when Ni and Si added in the form of Ni-38 wt.%Si, but not separately. Ni-38 wt.%Si alloy brings 'genetic materials' into the Al-Si melt, which makes the melt to form more ordering structure, promotes the primary Si precipitated. Moreover, the addition of Ni-38 wt.%Si, which decreases the solidification supercooling degree of Al-12 wt.%Si alloy, is identical to the effect of heterogeneous nuclei.

  7. Modification effect of Ni-38 wt.%Si on Al-12 wt.%Si alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wu Yuying [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Ji' nan 250061 (China)], E-mail: wyy532001@163.com; Liu Xiangfa [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Ji' nan 250061 (China); Shandong Binzhou Bohai Piston Co., Ltd., Binzhou 256602, Shandong (China); Jiang Binggang [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Ji' nan 250061 (China); Huang Chuanzhen [School of Mechanical Engineering, Shandong University, Jinan 250061 (China)

    2009-05-27

    Modification effect of Ni-38 wt.%Si on the Al-12 wt.%Si alloy has been studied by differential scanning calorimeter, torsional oscillation viscometer and liquid X-ray diffraction experiments. It is found that there is a modification effect of Ni-38 wt.%Si on Al-12 wt.%Si alloy, i.e. primary Si can precipitate in the microstructure of Al-12 wt.%Si alloy when Ni and Si added in the form of Ni-38 wt.%Si, but not separately. Ni-38 wt.%Si alloy brings 'genetic materials' into the Al-Si melt, which makes the melt to form more ordering structure, promotes the primary Si precipitated. Moreover, the addition of Ni-38 wt.%Si, which decreases the solidification supercooling degree of Al-12 wt.%Si alloy, is identical to the effect of heterogeneous nuclei.

  8. Method for accelerated leaching of solidified waste

    International Nuclear Information System (INIS)

    Fuhrmann, M.; Heiser, J.H.; Pietrzak, R.F.; Franz, E.M.; Colombo, P.

    1990-11-01

    An accelerated leach test method has been developed to determine the maximum leachability of solidified waste. The approach we have taken is to use a semi-dynamic leach test; that is, the leachant is sampled and replaced periodically. Parameters such as temperature, leachant volume, and specimen size are used to obtain releases that are accelerated relative to other standard leach tests and to the leaching of full-scale waste forms. The data obtained with this test can be used to model releases from waste forms, or to extrapolate from laboratory-scale to full-scale waste forms if diffusion is the dominant leaching mechanism. Diffusion can be confirmed as the leaching mechanism by using a computerized mathematical model for diffusion from a finite cylinder. We have written a computer program containing several models including diffusion to accompany this test. The program and a Users' Guide that gives screen-by-screen instructions on the use of the program are available from the authors. 14 refs., 4 figs., 1 tab

  9. Leaching behavior of cement solidified materials

    International Nuclear Information System (INIS)

    2002-03-01

    An immersion test of mortar was carried out in order to solidify waste with uranium. The sample consists of 2000g cement, 950g ion exchange water, 1600g sound and 1g water reducing agent. The solid sample and ion exchange water (100 of immersion liquid/original sample) was put into polystyrene closed vessel in globe box and kept four weeks, and then it was separated to the immersion liquid and the solid phase. New ion exchange water was added to the solid and kept four weeks and then separated. Its ratio showed 200. The analysis was done at 100, 200 and 300 ratio of immersion liquid/sample. The solid phase was studied by the powder X-ray diffraction analysis, thermo gravimetric analysis and chemical analysis. The liquid phase was determined by pH values and composition analysis. The results showed Ca(OH) 2 , cement hydrate, was flowed out and it was not found in the solid phase at 200 ratio. (S.Y.)

  10. Leaching studies of radionuclides from solidified wastes with thermosetting resin

    International Nuclear Information System (INIS)

    Suzuki, K.; Kuribayashi, H.; Morimitsu, W.; Ono, I.

    1982-01-01

    This paper reports on studies of the leachability of Co-60 and Cs-137 from simulated LWR radwastes solidified with thermosetting resin and evaluates the effects of chemical fixation on leachability. It is concluded that insolubilization by a nickel-ferrocyanide compound offers an effective chemical fixation of these radionuclides and is a recommended pretreating method for radwastes that are to be solidified. 2 figures

  11. Experimental Investigation of Closed Porosity of Inorganic Solidified Foam Designed to Prevent Coal Fires

    Directory of Open Access Journals (Sweden)

    Yi Lu

    2015-01-01

    Full Text Available In order to overcome the deficiency of the existing fire control technology and control coal spontaneous combustion by sealing air leakages in coal mines, inorganic solidified foam (ISF with high closed porosity was developed. The effect of sodium dodecyl sulfate (SDS concentration on the porosity of the foams was investigated. The results showed that the optimized closed porosity of the solidified foam was 38.65 wt.% for an SDS concentration of approximately 7.4×10-3 mol/L. Based on observations of the microstructure of the pore walls after solidification, it was inferred that an equilibrium between the hydration process and the drainage process existed. Therefore, the ISF was improved using three different systems. Gelatin can increase the viscosity of the continuous phase to form a viscoelastic film around the air cells, and the SDS + gelatin system can create a mixed surfactant layer at gas/liquid interfaces. The accelerator (AC accelerates the hydration process and coagulation of the pore walls before the end of drainage. The mixed SDS + gelatin + AC systems produced an ISF with a total porosity of 79.89% and a closed porosity of 66.89%, which verified the proposed stabilization mechanism.

  12. Structural investigations of mechanical properties of Al based rapidly solidified alloys

    International Nuclear Information System (INIS)

    Karakoese, Ercan; Keskin, Mustafa

    2011-01-01

    Highlights: → Rapid solidification processing (RSP) involves exceptionally high cooling rates. → We correlate the microstructure of the intermetallic Al 3 Fe, Al 2 Cu and Al 3 Ni phases with the cooling rate. → The solidification rate is high enough to retain most of alloying elements in the Al matrix. → The rapid solidification has effect on the phase constitution. -- Abstract: In this study, Al based Al-3 wt.%Fe, Al-3 wt.%Cu and Al-3 wt.%Ni alloys were prepared by conventional casting. They were further processed using the melt-spinning technique and characterized by the X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS), transmission electron microscope (TEM), differential scanning calorimetry (DSC) and the Vickers microhardness tester. The rapidly solidified (RS) binary alloys were composed of supersaturated α-Al solid solution and finely dispersed intermetallic phases. Experimental results showed that the mechanical properties of RS alloys were enhanced, which can be attributed to significant changes in the microstructure. RS samples were measured using a microhardness test device. The dependence of microhardness H V on the solidification rate (V) was analysed. These results showed that with the increasing values of V, the values of H V increased. The enthalpies of fusion for the same alloys were determined by DSC.

  13. Structure and mechanical properties of Al-3Fe rapidly solidified alloy

    International Nuclear Information System (INIS)

    Karakoese, Ercan; Keskin, Mustafa

    2011-01-01

    The Al based Al-3 wt%Fe alloy was prepared by conventionally casting (ingot) and further processed the melt-spinning technique and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) together with energy dispersive spectroscopy (EDS), differential scanning calorimetry (DSC) and the Vickers microhardness tester. The rapidly solidified (RS) binary alloys were composed of supersaturated α-Al solid solution and finely dispersed intermetallic phases. Experimental results showed that the mechanical properties of RS alloys were enhanced, which can be attributed to significant changes in the microstructure. The dependence of microhardness H V on the solidification rate (V) was analysed. These results showed that with the increasing values of V, the values of H V increased.

  14. Microstructure of rapidly solidified Al2O3-dispersion-strengthened Type 316 stainless steel

    International Nuclear Information System (INIS)

    Megusar, J.; Arnberg, L.; Vander Sande, J.B.; Grant, N.J.

    1981-01-01

    An aluminum oxide dispersion strengthened 316 stainless steel was developed by surface oxidation. Surface oxidation was chosen as a preferred method in order to minimize formation of less stable chromium oxides. Ultra low C+N 316 stainless steel was alloyed with 1 wt % Al, rapidly solidified to produce fine powders and attrited to approximately 0.5 μm thick flakes to provide for surface oxidation. Oxide particles in the extruded material were identified mostly as Al oxides. In the preirradiated condition, oxide dispersion retarded crystallization and grain growth and had an effect on room temperature tensile properties. These structural modifications are expected to have an effect on the swelling resistance, structure stability and high temperature strength of austenitic stainless steels

  15. Biodegradation testing of solidified low-level waste streams

    International Nuclear Information System (INIS)

    Piciulo, P.L.; Shea, C.E.; Barletta, R.E.

    1985-05-01

    The NRC Technical Position on Waste Form (TP) specifies that waste should be resistant to biodegradation. The methods recommended in the TP for testing resistance to fungi, ASTM G21, and for testing resistance to bacteria, ASTM G22, were carried out on several types of solidified simulated wastes, and the effect of microbial activity on the mechanical strength of the materials tested was examined. The tests are believed to be sufficient for distinguishing between materials that are susceptible to biodegradation and those that are not. It is concluded that failure of these tests should not be regarded of itself as an indication that the waste form will biodegrade to an extent that the form does not meet the stability requirements of 10 CFR Part 61. In the case of failure of ASTM G21 or ASTM G22 or both, it is recommended that additional data be supplied by the waste generator to demonstrate the resistance of the waste form to microbial degradation. To produce a data base on the applicability of the biodegradation tests, the following simulated laboratory-scale waste forms were prepared and tested: boric acid and sodium sulfate evaporator bottoms, mixed-bed bead resins and powdered resins each solidified in asphalt, cement, and vinyl ester-styrene. Cement solidified wastes supported neither fungal nor bacterial growth. Of the asphalt solidified wastes, only the forms of boric acid evaporator bottoms did not support fungal growth. Bacteria grew on all of the asphalt solidified wastes. Cleaning the surface of these waste forms did not affect bacterial growth and had a limited effect on the fungal growth. Only vinyl esterstyrene solidified sodium sulfate evaporator bottoms showed viable fungi cultures, but surface cleaning with solvents eliminated fungal growth in subsequent testing. Some forms of all the waste streams solidified in vinyl ester-styrene showed viable bacteria cultures. 13 refs., 12 tabs

  16. Parameters of Solidifying Mixtures Transporting at Underground Ore Mining

    Directory of Open Access Journals (Sweden)

    Golik Vladimir

    2017-01-01

    Full Text Available The article is devoted to the problem of providing mining enterprises with solidifying filling mixtures at underground mining. The results of analytical studies using the data of foreign and domestic practice of solidifying mixtures delivery to stopes are given. On the basis of experimental practice the parameters of transportation of solidifying filling mixtures are given with an increase in their quality due to the effect of vibration in the pipeline. The mechanism of the delivery process and the procedure for determining the parameters of the forced oscillations of the pipeline, the characteristics of the transporting processes, the rigidity of the elastic elements of pipeline section supports and the magnitude of vibrator’ driving force are detailed. It is determined that the quality of solidifying filling mixtures can be increased due to the rational use of technical resources during the transportation of mixtures, and as a result the mixtures are characterized by a more even distribution of the aggregate. The algorithm for calculating the parameters of the pipe vibro-transport of solidifying filling mixtures can be in demand in the design of mineral deposits underground mining technology.

  17. Parameters of Solidifying Mixtures Transporting at Underground Ore Mining

    Science.gov (United States)

    Golik, Vladimir; Dmitrak, Yury

    2017-11-01

    The article is devoted to the problem of providing mining enterprises with solidifying filling mixtures at underground mining. The results of analytical studies using the data of foreign and domestic practice of solidifying mixtures delivery to stopes are given. On the basis of experimental practice the parameters of transportation of solidifying filling mixtures are given with an increase in their quality due to the effect of vibration in the pipeline. The mechanism of the delivery process and the procedure for determining the parameters of the forced oscillations of the pipeline, the characteristics of the transporting processes, the rigidity of the elastic elements of pipeline section supports and the magnitude of vibrator' driving force are detailed. It is determined that the quality of solidifying filling mixtures can be increased due to the rational use of technical resources during the transportation of mixtures, and as a result the mixtures are characterized by a more even distribution of the aggregate. The algorithm for calculating the parameters of the pipe vibro-transport of solidifying filling mixtures can be in demand in the design of mineral deposits underground mining technology.

  18. Energy asymmetry in melting and solidifying processes of PCM

    International Nuclear Information System (INIS)

    Jin, Xing; Hu, Huoyan; Shi, Xing; Zhang, Xiaosong

    2015-01-01

    Highlights: • The melting process and the solidifying process of PCM were asymmetrical. • The enthalpy and state of PCM were affected by its previous state. • The main reason for energy asymmetry of PCM was supercooling. - Abstract: The solidifying process of phase change material (PCM) was usually recognized as the exact inverse process of its melting process, especially when building the heat transfer model of PCM. To figure out that whether the melting process and the solidifying process of PCM were symmetrical, several kinds of PCMs were tested by a differential scanning calorimeter (DSC) in this paper. The experimental results showed that no matter using the DSC dynamic measurement method or the DSC step measurement method, the melting process and the solidifying process of PCM were asymmetrical. Because of the energy asymmetry in the melting and solidifying processes of PCM, it was also found that the enthalpy and the state of PCM were not only dependent on its temperature, but also affected by its “previous state”.

  19. Method of solidifying and disposing radioactive waste plastic

    International Nuclear Information System (INIS)

    Matsuura, Hiroyuki; Yasumura, Keijiro

    1981-01-01

    Purpose: To solidify radioactive waste as it is with plastic by forming a W/O (Water-in-Oil) emulsion with the radioactive waste and a plastic solidifier, and treating it with a polymerization starting agent, an accelerator, and the like. Method: A predetermined amount of alkaline substance such as sodium hydroxide, triethanol, or the like is added quantitatively to radioactive waste and it is mixed by an agitator. A predetermined amount of solidifier such as unsaturated polyester or the like is added to the mixture and it is further mixed by the agitator to form a stable W/O emulsion. Subsequently, predetermined amounts of polymerization starting agent such as methyl ethyl ketone peroxide and polymerization accelerator such as cobalt naphthenate or the like are added thereto, the mixture is mixed, and is then allowed to stand for at room temperature for the plastic solidification thereof. No reaction occurs after the solidification. (Sekiya, K.)

  20. Controlled Directional Solidification of Aluminum - 7 wt Percent Silicon Alloys: Comparison Between Samples Processed on Earth and in the Microgravity Environment Aboard the International Space Station

    Science.gov (United States)

    Grugel, Richard N.; Tewari, Surendra N.; Erdman, Robert G.; Poirier, David R.

    2012-01-01

    An overview of the international "MIcrostructure Formation in CASTing of Technical Alloys" (MICAST) program is given. Directional solidification processing of metals and alloys is described, and why experiments conducted in the microgravity environment aboard the International Space Station (ISS) are expected to promote our understanding of this commercially relevant practice. Microstructural differences observed when comparing the aluminum - 7 wt% silicon alloys directionally solidified on Earth to those aboard the ISS are presented and discussed.

  1. Detection of free liquid in containers of solidified radioactive waste

    Science.gov (United States)

    Greenhalgh, Wilbur O.

    1985-01-01

    A method of nondestructively detecting the presence of free liquid within a sealed enclosure containing solidified waste by measuring the levels of waste at two diametrically opposite locations while slowly tilting the enclosure toward one of said locations. When the measured level remains constant at the other location, the measured level at said one location is noted and any measured difference of levels indicates the presence of liquid on the surface of the solidified waste. The absence of liquid in the enclosure is verified when the measured levels at both locations are equal.

  2. Evaluation of solidified high-level waste forms

    International Nuclear Information System (INIS)

    1981-01-01

    One of the objectives of the IAEA waste management programme is to coordinate and promote development of improved technology for the safe management of radioactive wastes. The Agency accomplished this objective specifically through sponsoring Coordinated Research Programmes on the ''Evaluation of Solidified High Level Waste Products'' in 1977. The primary objectives of this programme are to review and disseminate information on the properties of solidified high-level waste forms, to provide a mechanism for analysis and comparison of results from different institutes, and to help coordinate future plans and actions. This report is a summary compilation of the key information disseminated at the second meeting of this programme

  3. Properties of WZ21 (%wt) alloy processed by a powder metallurgy route.

    Science.gov (United States)

    Cabeza, Sandra; Garcés, Gerardo; Pérez, Pablo; Adeva, Paloma

    2015-06-01

    Microstructure, mechanical properties and corrosion behaviour of WZ21 (%wt) alloy prepared by a powder metallurgy route from rapidly solidified powders have been studied. Results were compared to those of the same alloy prepared through a conventional route of casting and extrusion. The microstructure of the extruded ingot consisted of α-Mg grains and Mg3Zn3Y2 (W-phase) and LPSO-phase particles located at grain boundaries. Moreover, stacking faults were also observed within α-Mg grains. The alloy processed by the powder metallurgy route exhibited a more homogeneous and finer microstructure, with a grain size of 2 μm. In this case W-phase and Mg24Y5 phase were identified, but not the LPSO-phase. The microstructural refinement induced by the use of rapidly solidified powders strengthened the alloy at room temperature and promoted superplasticity at higher strain rates. Corrosion behaviour in PBS medium evidenced certain physical barrier effect of the almost continuous arrangements of second phases aligned along the extrusion direction in conventionally processed WZ21 alloy, with a stable tendency around 7 mm/year. On the other hand, powder metallurgy processing promoted significant pitting corrosion, inducing accelerated corrosion rate during prolonged immersion times. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Secondary dendrite arm spacing and solute redistribution effects on the corrosion resistance of Al-10 wt% Sn and Al-20 wt% Zn alloys

    International Nuclear Information System (INIS)

    Osorio, Wislei R.; Spinelli, Jose E.; Cheung, Noe; Garcia, Amauri

    2006-01-01

    In general, aluminum alloys provide the most significant part of all shaped casting manufactured. An optimum range of properties can be obtained as a function of different cooling rate processes, such as sand, plaster, investment, permanent molds and die castings. It is well known that the dendritic network affects not only the mechanical properties but also the corrosion resistance. However, the literature is scarce on reports concerning the influences of dendrite arm spacing on corrosion resistance and mechanical behavior. The aim of this study is to investigate the influence of as-cast microstructure features, i.e., dendrite arm spacing and solute redistribution on the corrosion resistance of samples of aluminum alloys. In order to investigate the electrochemical behavior of solute and solvent of different aluminum systems, samples with the same order of magnitude of dendritic spacings were analyzed to permit comparison between Al-10 wt% Sn and Al-20 wt% Zn alloys. A casting water-cooled assembly promoting upward directional solidification was used in order to obtain controlled casting samples of these alloys. In order to characterize the dendritic structure, longitudinal sections from the directionally solidified specimens were analyzed by using optical and electronic microscopy techniques. The corrosion resistance was analyzed by both the electrochemical impedance spectroscopy technique and Tafel extrapolation method conducted in a 3% NaCl solution at room temperature. Although both systems present an Al-rich dendritic matrix, different responses to corrosive action as a function of dendritic spacing have been detected

  5. Secondary dendrite arm spacing and solute redistribution effects on the corrosion resistance of Al-10 wt% Sn and Al-20 wt% Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, Wislei R. [Department of Materials Engineering, State University of Campinas-UNICAMP, P.O. Box 6122, 13083-970 Campinas, SP (Brazil); Spinelli, Jose E. [Department of Materials Engineering, State University of Campinas-UNICAMP, P.O. Box 6122, 13083-970 Campinas, SP (Brazil); Cheung, Noe [Department of Materials Engineering, State University of Campinas-UNICAMP, P.O. Box 6122, 13083-970 Campinas, SP (Brazil); Garcia, Amauri [Department of Materials Engineering, State University of Campinas-UNICAMP, P.O. Box 6122, 13083-970 Campinas, SP (Brazil)]. E-mail: amaurig@fem.unicamp.br

    2006-03-25

    In general, aluminum alloys provide the most significant part of all shaped casting manufactured. An optimum range of properties can be obtained as a function of different cooling rate processes, such as sand, plaster, investment, permanent molds and die castings. It is well known that the dendritic network affects not only the mechanical properties but also the corrosion resistance. However, the literature is scarce on reports concerning the influences of dendrite arm spacing on corrosion resistance and mechanical behavior. The aim of this study is to investigate the influence of as-cast microstructure features, i.e., dendrite arm spacing and solute redistribution on the corrosion resistance of samples of aluminum alloys. In order to investigate the electrochemical behavior of solute and solvent of different aluminum systems, samples with the same order of magnitude of dendritic spacings were analyzed to permit comparison between Al-10 wt% Sn and Al-20 wt% Zn alloys. A casting water-cooled assembly promoting upward directional solidification was used in order to obtain controlled casting samples of these alloys. In order to characterize the dendritic structure, longitudinal sections from the directionally solidified specimens were analyzed by using optical and electronic microscopy techniques. The corrosion resistance was analyzed by both the electrochemical impedance spectroscopy technique and Tafel extrapolation method conducted in a 3% NaCl solution at room temperature. Although both systems present an Al-rich dendritic matrix, different responses to corrosive action as a function of dendritic spacing have been detected.

  6. Solidification analysis of a centrifugal atomizer using the Al-32.7wt.% Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Osborne, Matthew G. [Iowa State Univ., Ames, IA (United States)

    1998-02-23

    A centrifugal atomizer (spinning disk variety) was designed and constructed for the production of spherical metal powders, 100-1,000 microns in diameter in an inert atmosphere. Initial atomization experiments revealed the need for a better understanding of how the liquid metal was atomized and how the liquid droplets solidified. To investigate particle atomization, Ag was atomized in air and the process recorded on high-speed film. To investigate particle solidification, Al-32.7 wt.% Cu was atomized under inert atmosphere and the subsequent particles were examined microscopically to determine solidification structure and rate. This dissertation details the experimental procedures used in producing the Al-Cu eutectic alloy particles, examination of the particle microstructures, and determination of the solidification characteristics (e.g., solidification rate) of various phases. Finally, correlations are proposed between the operation of the centrifugal atomizer and the observed solidification spacings.

  7. Site suitability criteria for solidified high level waste repositories

    International Nuclear Information System (INIS)

    Heckman, R.A.; Holdsworth, T.; Towse, D.F.

    1979-01-01

    Activities devoted to development of regulations, criteria, and standards for storage of solidified high-level radioactive wastes are reported. The work is summarized in sections on site suitability regulations, risk calculations, geological models, aquifer models, human usage model, climatology model, and repository characteristics. Proposed additional analytical work is also summarized

  8. Characteristics of solidified high-level waste products

    International Nuclear Information System (INIS)

    1979-01-01

    The object of the report is to contribute to the establishment of a data bank for future preparation of codes of practice and standards for the management of high-level wastes. The work currently in progress on measuring the properties of solidified high-level wastes is being studied

  9. Photolysis of rhodamine-WT dye

    Science.gov (United States)

    Tai, D.Y.; Rathbun, R.E.

    1988-01-01

    Photolysis of rhodamine-WT dye under natural sunlight conditions was determined by measuring the loss of fluorescence as a function of time. Rate coefficients at 30?? north latitude ranged from 4.77 x 10-2 day-1 for summer to 3.16 x 10-2 day-1 for winter. Experimental coefficients were in good agreement with values calculated using a laboratory-determined value of the quantum yield.

  10. Physical and electrical properties of melt-spun Fe-Si (3–8 wt.%) soft magnetic ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Overman, Nicole R.; Jiang, Xiujuan; Kukkadapu, Ravi K.; Clark, Trevor; Roosendaal, Timothy J.; Coffey, Gregory; Shield, Jeffrey E.; Mathaudhu, Suveen N.

    2018-02-01

    Fe-Si alloys ranging from 3 to 8 wt% Si were rapidly solidified using melt spinning. Wheel speeds of 30 m/s and 40 m/s were employed to vary cooling rates. Mössbauer spectroscopic studies indicated the Si content significantly influenced the number of Fe sites, relative abundance of various Fe species, and internal magnetic fields/structural environments. Wheel speed altered Fe speciation only in the 3 wt% sample. Scanning electron microscopy confirmed that increasing the wheel speed refined both the ribbon thickness and grain size. Electron backscatter diffraction results suggest tailoring melt spinning process parameters and alloy chemistry may offer the ability to manipulate {001} texture development. Electrical resistivity measurements were observed to increase in response to elevated Si content. Increased hardness was correlated to elevated Si content and wheel speed.

  11. Propertis of solidified radioactive wastes from commercial LWRs

    International Nuclear Information System (INIS)

    Neilson, R.M. Jr.; Colombo, P.

    1978-01-01

    A study has been performed to characterize the properties of solidified radioactive wastes generated in the liquid radwaste treatment systems at LWRs. The properties which have been studied are those which are pertinent in defining the relative potential for the release of radionuclides to the environment as well as others relating to the evaluation of various solidification agents on an economic and feasibility basis. The use of standard testing procedures in measuring these properties allows an intercomparison of respective properties between various types of solidified waste forms. The leachability, mechanical properties, thermal stability, radiation stability, and thermal properties of hydraulic cement, ureaformaldehyde, bitumen, and addition type polymer waste forms have been measured. In addition, the chemical sensitivity, volumetric efficiency and radiation shielding characteristics of these waste forms have been studied. Emphasis in this paper is placed on the results of studies concerning chemical compatibility of solidification agents with specific waste streams, volumetric efficiency, free standing water, and leachability

  12. Production and properties of solidified high-level waste

    International Nuclear Information System (INIS)

    Brodersen, K.

    1980-08-01

    Available information on production and properties of solidified high-level waste are presented. The review includes literature up to the end of 1979. The feasibility of production of various types of solidified high-level wast is investigated. The main emphasis is on borosilicate glass but other options are also mentioned. The expected long-term behaviour of the materials are discussed on the basis of available results from laboratory experiments. Examples of the use of the information in safety analysis of disposal in salt formations are given. The work has been made on behalf of the Danish utilities investigation of the possibilities of disposal of high-level waste in salt domes in Jutland. (author)

  13. Mechanical Properties of 0.14wt%C – 0.56wt%Mn – 0.13wt%Si ...

    African Journals Online (AJOL)

    Effect of intercritical heat treatment on 0.14wt%C – 0.56wt%Mn – 0.13wt%Si structural steel has been investigated. Specimens for single quenching and those for double quenching were prepared for intercritical heat treatment. The heat treatment of the experimental steel was based on intercritical annealing in the ferrite + ...

  14. Characterization of rapidly solidified powder of high-speed steel

    Czech Academy of Sciences Publication Activity Database

    Miglierini, M.; Lančok, Adriana; Kusý, M.

    2009-01-01

    Roč. 190, 1-3 (2009), s. 51-57 ISSN 0304-3843 R&D Projects: GA ČR GP203/07/P011 Grant - others:GA(SK) VEGA1/3190/06 Institutional research plan: CEZ:AV0Z40320502 Keywords : Rapidly solidified powder * Tool steel * Mössbauer spectroscopy Subject RIV: CA - Inorganic Chemistry Impact factor: 0.209, year: 2007

  15. Rapidly solidified prealloyed powders by laser spin atomization

    Science.gov (United States)

    Konitzer, D. G.; Walters, K. W.; Heiser, E. L.; Fraser, H. L.

    1984-01-01

    A new technique, termed laser spin atomization, for the production of rapidly solidified prealloyed powders is described. The results of experiments involving the production of powders of two alloys, one based on Ni, the other on Ti, are presented. The powders have been characterized using light optical metallography, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Auger elec-tron spectroscopy, and these various observations are described.

  16. Isolating $Wt$ production at the LHC

    CERN Document Server

    White, Chris D; Laenen, Eric; Maltoni, Fabio

    2009-01-01

    We address the issue of single top production in association with a W boson at the Large Hadron Collider, in particular how to obtain an accurate description in the face of the top pair production background given that the two processes interfere with each other. We stress the advantages of an MC@NLO description, and find that for cuts used to isolate the signal, it makes sense to consider Wt as a well-defined production process in that the interference with top pair production is small, and the cross-section of the former is above the scale variation uncertainty associated with the latter. We also consider the case where both Wt and top pair production are backgrounds to a third process (Higgs boson production followed by decay to a W boson pair), and find in this context that interference issues can also be neglected. We discuss the generalization of our results to other situations, aided by a comparison between the MC@NLO approach and a calculation of the WWbb final state matched to a parton shower.

  17. Influence of carbonation on the acid neutralization capacity of cements and cement-solidified/stabilized electroplating sludge.

    Science.gov (United States)

    Chen, Quanyuan; Zhang, Lina; Ke, Yujuan; Hills, Colin; Kang, Yanming

    2009-02-01

    Portland cement (PC) and blended cements containing pulverized fuel ash (PFA) or granulated blast-furnace slag (GGBS) were used to solidify/stabilize an electroplating sludge in this work. The acid neutralization capacity (ANC) of the hydrated pastes increased in the order of PC > PC/GGBS > PC/PFA. The GGBS or PFA replacement (80 wt%) reduced the ANC of the hydrated pastes by 30-50%. The ANC of the blended cement-solidified electroplating sludge (cement/sludge 1:2) was 20-30% higher than that of the hydrated blended cement pastes. Upon carbonation, there was little difference in the ANC of the three cement pastes, but the presence of electroplating sludge (cement/sludge 1:2) increased the ANC by 20%. Blended cements were more effective binders for immobilization of Ni, Cr and Cu, compared with PC, whereas Zn was encapsulated more effectively in the latter. Accelerated carbonation improved the immobilization of Cr, Cu and Zn, but not Ni. The geochemical code PHREEQC, with the edited database from EQ3/6 and HATCHES, was used to calculate the saturation index and solubility of likely heavy metal precipitates in cement-based solidification/stabilization systems. The release of heavy metals could be related to the disruption of cement matrices and the remarkable variation of solubility of heavy metal precipitates at different pH values.

  18. Effect of thermal cycling on the microstructure of a directionally solidified Fe, Cr, Al-TaC eutectic alloy

    Science.gov (United States)

    Harf, F. H.; Tewari, S. N.

    1977-01-01

    Cylindrical bars (1.2 cm diameter) of Fe-13.6Cr-3.7Al-9TaC (wt %) eutectic alloy were directionally solidified in a modified Bridgman type furnace at 1 cm/h. The alloy microstructure consisted of aligned TaC fibers imbedded in a bcc Fe-Cr-Al matrix. Specimens of the alloy were thermally cycled from 1100 to 425 C in a burner rig. The effects of 1800 thermal cycles on the microstructure was examined by scanning electron microscopy, revealing a zig-zag shape of TaC fibers aligned parallel to the growth direction. The mechanism of carbide solution and reprecipitation on the (111) easy growth planes, suggested previously to account for the development of irregular serrations in Co-Cr-Ni matrix alloys, is believed to be responsible for these zig-zag surfaces.

  19. Organic semiconductor rubrene thin films deposited by pulsed laser evaporation of solidified solutions

    Science.gov (United States)

    Majewska, N.; Gazda, M.; Jendrzejewski, R.; Majumdar, S.; Sawczak, M.; Śliwiński, G.

    2017-08-01

    Organic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm2(V·s)-1. However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic solvents toluene, xylene, dichloromethane and 1,1-dichloroethane (0.23-1% wt) were cooled to temperatures in the range of 16.5-163 K and served as targets. The target ablation was provided by a pulsed 1064 nm or 266 nm laser. For films of thickness up to 100 nm deposited on Si, glass and ITO glass substrates, the Raman and AFM data show presence of the mixed crystalline and amorphous rubrene phases. Agglomerates of rubrene crystals are revealed by SEM observation too, and presence of oxide/peroxide (C42H28O2) in the films is concluded from matrix-assisted laser desorption/ionization time-of-flight spectroscopic analysis.

  20. Solidifier effectiveness : variation due to oil composition, oil thickness and temperature

    International Nuclear Information System (INIS)

    Fieldhouse, B.; Fingas, M.

    2009-01-01

    This paper provided an overview of solidifier types and composition. Solidifiers are a class of spill treating agents that offer an effective means to convert a liquid oil into a solid material. They are used as a treatment option for oil spills on water. This paper also reported on recent laboratory studies that consist of 4 components: (1) a qualitative examination of the characteristics of the interaction of a broad range of solidifier products with a standard oil to evaluate reaction rate, states of solidification, and the impact of dosage, (2) a comparison of a smaller subset of solidifiers on the standard oil at lower temperatures, (3) solidifier treatment on a range of oils of varying physical properties and composition to assess the potential scope of application, and (4) the treatment of a series of small-scale oil layers of varying thickness to determine the significance of oil thickness on solidifier effectiveness and recovery. This paper also reviewed solidifier chemistry with particular reference to polymer sorbents; cross-linking agents; and cross-linking agents and polymeric sorbents combined. Toxicity is also an important issue regarding solidifiers. The aquatic toxicity of solidifiers is low and not measurable as the products are not water-soluble. There have not been any studies on the effects of the solidifier or the treated oil on surface feeders and shoreline wildlife that may come into contact with the products. It was concluded that oil composition may play a major role in solidifier effectiveness. The effectiveness of solidifiers is also inhibited at reduced temperatures, increased viscosity and density of the oil. 25 refs., 5 tabs., 2 figs., 1 appendix

  1. Micro and Macro Segregation in Alloys Solidifying with Equiaxed Morphology

    Science.gov (United States)

    Stefanescu, Doru M.; Curreri, Peter A.; Leon-Torres, Jose; Sen, Subhayu

    1996-01-01

    To understand macro segregation formation in Al-Cu alloys, experiments were run under terrestrial gravity (1g) and under low gravity during parabolic flights (10(exp -2) g). Alloys of two different compositions (2% and 5% Cu) were solidified at two different cooling rates. Systematic microscopic and SEM observations produced microstructural and segregation maps for all samples. These maps may be used as benchmark experiments for validation of microstructure evolution and segregation models. As expected, the macro segregation maps are very complex. When segregation was measured along the central axis of the sample, the highest macro segregation for samples solidified at 1g was obtained for the lowest cooling rate. This behavior is attributed to the longer time available for natural convection and shrinkage flow to affect solute redistribution. In samples solidified under low-g, the highest macro-segregation was obtained at the highest cooling rate. In general, low-gravity solidification resulted in less segregation. To explain the experimental findings, an analytical (Flemings-Nereo) and a numerical model were used. For the numerical model, the continuum formulation was employed to describe the macroscopic transports of mass, energy, and momentum, associated with the microscopic transport phenomena, for a two-phase system. The model proposed considers that liquid flow is driven by thermal and solutal buoyancy, and by solidification shrinkage. The Flemings-Nereo model explains well macro segregation in the initial stages of low-gravity segregation. The numerical model can describe the complex macro segregation pattern and the differences between low- and high-gravity solidification.

  2. Nickel speciation in cement-stabilized/solidified metal treatment filtercakes

    Energy Technology Data Exchange (ETDEWEB)

    Roy, Amitava, E-mail: reroy@lsu.edu [J. Bennett Johnston, Sr., Center for Advanced Microstructures and Devices, Louisiana State University, Baton Rouge, LA 70806, USA (United States); Stegemann, Julia A., E-mail: j.stegemann@ucl.ac.uk [Centre for Resource Efficiency & the Environment, Department of Civil, Environmental & Geomatic Engineering, University College London, Chadwick Building, Gower Street, London WC1E 6BT, UK (United Kingdom)

    2017-01-05

    Highlights: • XAS shows the same Ni speciation in untreated and stabilized/solidified filtercake. • Ni solubility is the same for untreated and stabilized/solidified filtercake. • Leaching is controlled by pH and physical encapsulation for all binders. - Abstract: Cement-based stabilization/solidification (S/S) is used to decrease environmental leaching of contaminants from industrial wastes. In this study, two industrial metal treatment filtercakes were characterized by X-ray diffractometry (XRD), thermogravimetric and differential thermogravimetric analysis (TG/DTG) and Fourier transform infrared (FTIR); speciation of nickel was examined by X-ray absorption (XAS) spectroscopy. Although the degree of carbonation and crystallinity of the two untreated filtercakes differed, α-nickel hydroxide was identified as the primary nickel-containing phase by XRD and nickel K edge XAS. XAS showed that the speciation of nickel in the filtercake was unaltered by treatment with any of five different S/S binder systems. Nickel leaching from the untreated filtercakes and all their stabilized/solidified products, as a function of pH in the acid neutralization capacity test, was essentially complete below pH ∼5, but was 3–4 orders of magnitude lower at pH 8–12. S/S does not respeciate nickel from metal treatment filtercakes and any reduction of nickel leaching by S/S is attributable to pH control and physical mechanisms only. pH-dependent leaching of Cr, Cu and Ni is similar for the wastes and s/s products, except that availability of Cr, Cu and Zn at decreased pH is reduced in matrices containing ground granulated blast furnace slag.

  3. Detection of free liquid in containers of solidified radioactive waste

    Science.gov (United States)

    Greenhalgh, W.O.

    Nondestructive detection of the presence of free liquid within a sealed enclosure containing solidified waste is accomplished by measuring the levels of waste at two diametrically opposite locations while slowly tilting the enclosure toward one of said locations. When the measured level remains constant at the other location, the measured level at said one location is noted and any measured difference of levels indicates the presence of liquid on the surface of the solifified waste. The absence of liquid in the enclosure is verified when the measured levels at both locations are equal.

  4. Undercooling and demixing in rapidly solidified Cu-Co alloys

    DEFF Research Database (Denmark)

    Battezzati, L.; Curiotto, S.; Johnson, Erik

    2007-01-01

    The Cu–Co system displays a metastable miscibility gap in the liquid state. A considerable amount of work has been performed to study phase separation and related microstructures showing that demixing of the liquid is followed by coagulation before dendritic solidification. Due to kinetic...... competition of transformation phenomena, the mechanisms have not been fully disclosed. This contribution reviews such findings with the help of a computer calculation of the phase diagram and extends the present knowledge by presenting new results obtained by rapidly solidifying various Cu–Co compositions...... using a wide range of cooling rates achieved by forcing the liquid into cylindric and conic moulds and by melt spinning....

  5. Filling of recovered mining areas using solidifying backfill

    Directory of Open Access Journals (Sweden)

    Zeman Róbert

    2001-12-01

    Full Text Available The aim of this article is to explore the possibilities for filling recovered mining areas using solidifying backfill .The article describes the preparation of the backfill (backfill formulation with an eventual application using low quality sands, wastes from treatment plants and ash from power plants etc now to transport it as well as its application in practice. Advantageous and disadvantageous of this method are also mentioned.Several factors must be taken info consideration during the preparation process of the backfill mixture. Firstly, the quantities of each individual component must be constantly regulated. Secondly, the properties of each component must be respected. In addition, the needs of the pipeline transport system and the specific conditions of the recovered area to be filled must also be considered.Hydraulic transport and pneumo-hydraulic pipeline transport are used for handling the backfill. Pumps for transporting the solidifying backfill have to carry out demanding tasks.Due to the physical-mechanical properties of the backfill, only highly powerful pumps can be considered. Piston type pumps such as Abel Simplex and Duplex pumps with capacities of up to 100 m3.h-1 and operating pressures of up to 16 MPa would be suitable.This method has been applied abroad for different purposes. For example, solid backfill was used in the Hamr mine during exploitation of uranium using the room-and-pillar system mining method.In the Ostrava–Karvina Coal field, backfill was used in decontamination work, filling areas in a zone of dangerous deformations and for creating a dividing stratum during thick seam mining.Research info the use of solidifying backfill was also done in the Walsum mine in Germany. The aim of this research was:- to investigate the possibilities of filling a collapsing area in a working face using a solidifying mixture of power plant ash and water,- to verify whether towing pipelines proposed by the DMT corporation would be

  6. Study on dissolution behavior of molten solidified waste

    International Nuclear Information System (INIS)

    Mizuno, Tsuyoshi; Maeda, Toshikatsu

    2005-01-01

    Radioactive molten solidified waste (slag) has been generated by melting non-metallic low-level radioactive wastes (LLW). Slag is expected to immobilize radionuclides in the waste repository. The chemical durability of slag is an important factor for the safety assessment of the disposal in that the durability provides the source term in the assessment. Since a chemical characteristic of slag is similar to that of glass, the general information on the chemical durability of slag might be provided from previous studies on nuclear waste glass. We have investigated effects of chemical compositions of slag and alkaline environments of repository on the chemical durability of slag. (author)

  7. Increasing TRIGA fuel lifetime with 12 wt.% U TRIGA fuel

    Energy Technology Data Exchange (ETDEWEB)

    Naughton, W F; Cenko, M J; Levine, S H; Witzig, W F [Pennsylvania State University (United States)

    1974-07-01

    In-core fuel management studies have been performed for the Penn State Breazeale Reactor (PSBR) wherein 12 wt % U fuel elements are used to replace the standard 8.5 wt % U TRIGA fuel. The core configuration used to develop a calculational model was a 90-element hexagonal array, which is representative of the PSBR core, and consists of five hexagonal rings surrounding a central thimble containing water. The technique employed for refueling the core fully loaded with 8.5 wt % U fuel involves replacing 8.5 wt % U fuel with 12 wt % U fuel using an in-out reloading scheme. A batch reload consists of 6 new 12 wt % U fuel elements. Placing the 12 wt % U fuel in the B ring produces fuel temperatures ({approx}450 {sup o}C) that are well below the 800{sup o}C maximum limitation when the PSBR is operating at its maximum allowed power of 1 Megawatt. The advantages of using new 12 wt % U fuel to replace the burned up 8.5 wt % U fuel in the B ring over refueling strictly with 8.5 wt % U-Zr TRIGA fuel are clearly delineated in Table 1 where cost calculations used the General Atomic pre-1972 prices for TRIGA fuel, i.e., $1500 and $1650 for an 8.5 and 12 wt % U fuel element, respectively. Experimental results obtained to date utilizing the 12 wt % U fuel elements agree with the computed results. (author)

  8. Effect of swaging on the 1000 C compressive slow plastic flow characteristics of the directionally solidified eutectic alloy gamma/gamma prime-alpha

    Science.gov (United States)

    Whittenberger, J. D.; Wirth, G.

    1983-01-01

    Swaging between 750 and 1050 C has been investigated as a means to introduce work into the directionally solidified eutectic alloy gamma/gamma prime-alpha (Ni-32.3 wt percent Mo-6.3 wt percent Al) and increase the elevated temperature creep strength. The 1000 C slow plastic compressive flow stress-strain rate properties in air of as-grown, annealed, and worked nominally 10 and 25 percent materials have been determined. Swaging did not improve the slow plastic behavior. In fact large reductions tended to degrade the strength and produced a change in the deformation mechanism from uniform flow to one involving intense slip band formation. Comparison of 1000 C tensile and compressive strength-strain rate data reveals that deformation is independent of the stress state.

  9. Infiltration Behavior Of Mechanical Alloyed 75 wt% Cu-25 wt% WC Powders Into Porous WC Compacts

    Directory of Open Access Journals (Sweden)

    Şelte A.

    2015-06-01

    Full Text Available In this work infiltration behavior of mechanical alloyed 75 wt% Cu – 25 wt% WC powders into porous WC compacts were studied. Owing to their ductile nature, initial Cu powders were directly added to mechanical alloying batch. On the other hand initial WC powders were high energy milled prior to mechanical alloying. Contact infiltration method was selected for densification and compacts prepared from processed powders were infiltrated into porous WC bodies. After infiltration, samples were characterized via X-Ray diffraction studies and microstructural evaluation of the samples was carried out via scanning electron microscopy observations. Based on the lack of solubility between WC and Cu it was possible to keep fine WC particles in Cu melt since solution reprecipitation controlled densification is hindered. Also microstructural characterizations via scanning electron microscopy confirmed that the transport of fine WC fraction from infiltrant to porous WC skeleton can be carried out via Cu melt flow during infiltration.

  10. Phase development in a U-7 wt.% Mo vs. Al-7 wt.% Ge diffusion couple

    Science.gov (United States)

    Perez, E.; Keiser, D. D.; Sohn, Y. H.

    2013-10-01

    Fuel development for the Reduced Enrichment for Research and Test Reactors (RERTR) program has demonstrated that U-Mo alloys in contact with Al develop interaction regions with phases that have poor irradiation behavior. The addition of Si to the Al has been considered with positive results. In this study, compositional modification is considered by replacing Si with Ge to determine the effect on the phase development in the system. The microstructural and phase development of a diffusion couple of U-7 wt.% Mo in contact with Al-7 wt.% Ge was examined by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy. The interdiffusion zone developed a microstructure that included the cubic-UGe3 phase and amorphous phases. The UGe3 phase was observed with and without Mo and Al solid solution developing a (U,Mo)(Al,Ge)3 phase.

  11. Phase development in a U–7 wt.% Mo vs. Al–7 wt.% Ge diffusion couple

    Energy Technology Data Exchange (ETDEWEB)

    Perez, E., E-mail: Emmanuel.Perez@inl.gov [Nuclear Fuels and Materials Development, Idaho National Laboratory, Box 1625, Idaho Falls, ID 83415 (United States); Keiser, D.D. [Nuclear Fuels and Materials Development, Idaho National Laboratory, Box 1625, Idaho Falls, ID 83415 (United States); Sohn, Y.H. [Advanced Materials Processing and Analysis Center, and Department of Materials Science and Engineering, University of Central Florida, 4000 Central Florida Blvd., Orlando, FL 32816 (United States)

    2013-10-15

    Fuel development for the Reduced Enrichment for Research and Test Reactors (RERTR) program has demonstrated that U–Mo alloys in contact with Al develop interaction regions with phases that have poor irradiation behavior. The addition of Si to the Al has been considered with positive results. In this study, compositional modification is considered by replacing Si with Ge to determine the effect on the phase development in the system. The microstructural and phase development of a diffusion couple of U–7 wt.% Mo in contact with Al–7 wt.% Ge was examined by transmission electron microscopy, scanning electron microscopy and energy dispersive spectroscopy. The interdiffusion zone developed a microstructure that included the cubic-UGe{sub 3} phase and amorphous phases. The UGe{sub 3} phase was observed with and without Mo and Al solid solution developing a (U,Mo)(Al,Ge){sub 3} phase.

  12. Hardness and microstructure of Al-10.0 wt% Zn-4.0 wt% Mg alloy

    International Nuclear Information System (INIS)

    Iqbal, M.; Shaikh, M.A.; Ahmad, W.; Ali, K.L.

    1996-01-01

    Al-Zn-Mg alloys are widely used in industries as these have excellent physical and mechanical properties. However some aspects of the effect of heat treatment on these alloys are not yet clear. In order to understand the precipitation phenomena in these alloys, microstructure of a locally prepared alloy Al-10.0 wt% Zn-4.0 wt% Mg heat treated under different conditions has been examined in scanning electron microscope/electron probe micro analyser. Precipitates MgZn/sub 2/, MgZn/sub 4/ and Mg/sub 2/Zn/sub 11/ have been observed and these are caused by heat treatment. Correlation between these precipitates and Vickers's hardness has also been studied. In the present paper results of this investigation have been presented and discussed. (author)

  13. Solidified ceramics of radioactive wastes and method of producing it

    International Nuclear Information System (INIS)

    Oota, Takao; Matake, Shigeru; Ooka, Kazuo.

    1980-01-01

    Purpose: To provide solidified ceramics which have low leaching properties to water of radioactive substance, excellent heat dissipating and resistive properties and high mechanical strength by mixing and sintering limited amounts of titanium and aluminum compounds with calcined radioactive wastes containing special compound. Method: More than 20% by weight of titanium compound (as TiO 2 ) and more than 5% by weight of aluminum compound (as Al 2 O 3 ) are mixed with the calcined radioactive wasted containing, as converted by oxide, 5 to 40% by weight of Na 2 O, 5 to 20% by weight of Fe 2 O 3 , 5 to 15% by weight of MoO 3 , 5 to 15% by weight of ZrO 2 , 2 to 10% by weight of CeO 2 , 2 to 10% by weight of Cs 2 O, 1 to 5% by weight of BaO, 1 to 5% by weight of SrO, 0.2 to 2% by weight of Rb 2 O, 0.2% by weight of Y 2 O 3 , 0.2 to 2% by weight of NiO, 5 to 20% by weight of rare earth metal oxide, and 0.2 to 2% by weight of Cr 2 O 3 . The mixture is molded, sintered, and solidified to ceramics which contains no Mo phase, Na 2 O, MoO 3 , K 2 O, MoO 3 and Cs 2 O, MoO 3 phases and the like. (Yoshino, Y.)

  14. Leaching experiment of cement solidified waste form under unsaturated condition

    International Nuclear Information System (INIS)

    Wang Zhiming; Yao Laigen; Li Shushen; Zhao Yingjie; Cai Yun; Li Dan; Han Xinsheng; An Yongfeng

    2003-01-01

    A device for unsaturated leaching experiments was designed and built up. 8 different sizes, ranging from 40.2 cm 3 to 16945.5 cm 3 , of solidified waste form were tested in the experiment. 5 different water contents, from 0.15 to 0.40, were used for the experiment. The results show that the cumulative leaching fraction increases with water content when the sizes of the forms are equal to and less than 4586.7 cm 3 , for example, the ratios of the cumulative leaching fractions are between 1.24-1.41 under water content of 0.35 and 0.15 on 360 day of Teaching. It can also be seen that the cumulative leaching fraction under higher water content is close to that under saturated condition. The cumulative leaching fraction decreases with size of the form. Maximum leached depth of the solidified waste forms is about 2.25 cm after one year Teaching. Moreover, it has no clear effect on cumulative leaching fraction that sampling or non-sampling during the experiment

  15. Vessel for solidifying water-impermeable radioactive waste

    International Nuclear Information System (INIS)

    Kiuchi, Yoshimasa; Tamada, Shin; Suzuki, Yasushi.

    1993-01-01

    A blend prepared by admixing silica sand, alumina powder or glass fiber, as aggregates, to epoxy resin elastic adhesives is coated on an inner surface of a steel drum can or an inner surface of a concrete vessel at a thickness of greater than 1mm followed by hardening. The addition amount of the silica sand, alumina powder or glass fiber is determined as 20 to 40% by weight, 30 to 60% by weight or 5 to 15% by weight respectively. A lid having a hole for injecting fillers is previously bonded to a container for use in solidifying radioactive materials. The strength of the coating layer is increased and a coating performance and an adhesion force are improved by admixing the aggregates, to provide a satisfactory water-impermeability. The container for use in solidifying radioactive wastes having a coating layer with an advantage of the elastic resin adhesives, strong strength and adhesion and being excellent in the water-impermeability can be obtained relatively economically. (N.H.)

  16. Detachment of Tertiary Dendrite Arms during Controlled Directional Solidification in Aluminum - 7 wt Percent Silicon Alloys: Observations from Ground-based and Microgravity Processed Samples

    Science.gov (United States)

    Grugel, Richard N.; Erdman, Robert; Van Hoose, James R.; Tewari, Surendra; Poirier, David

    2012-01-01

    Electron Back Scattered Diffraction results from cross-sections of directionally solidified aluminum 7wt% silicon alloys unexpectedly revealed tertiary dendrite arms that were detached and mis-oriented from their parent arm. More surprisingly, the same phenomenon was observed in a sample similarly processed in the quiescent microgravity environment aboard the International Space Station (ISS) in support of the joint US-European MICAST investigation. The work presented here includes a brief introduction to MICAST and the directional solidification facilities, and their capabilities, available aboard the ISS. Results from the ground-based and microgravity processed samples are compared and possible mechanisms for the observed tertiary arm detachment are suggested.

  17. Effects of leachate concentration on the integrity of solidified clay liners.

    Science.gov (United States)

    Xue, Qiang; Zhang, Qian

    2014-03-01

    This study aimed to evaluate the impact of landfill leachate concentration on the degradation behaviour of solidified clay liners and to propose a viable mechanism for the observed degradation. The results indicated that the unconfined compressive strength of the solidified clay decreased significantly, while the hydraulic conductivity increased with the leachate concentration. The large pore proportion in the solidified clay increased and the sum of medium and micro pore proportions decreased, demonstrating that the effect on the solidified clay was evident after the degradation caused by exposure to landfill leachate. The unconfined compressive strength of the solidified clay decreased with increasing leachate concentration as the leachate changed the compact structure of the solidified clay, which are prone to deformation and fracture. The hydraulic conductivity and the large pore proportion of the solidified clay increased with the increase in leachate concentration. In contrast, the sum of medium and micro pore proportions showed an opposite trend in relation to leachate concentration, because the leachate gradually caused the medium and micro pores to form larger pores. Notably, higher leachate concentrations resulted in a much more distinctive variation in pore proportions. The hydraulic conductivity of the solidified clay was closely related to the size, distribution, and connection of pores. The proportion of the large pores showed a positive correlation with the increase of hydraulic conductivity, while the sum of the proportions of medium and micro pores showed a negative correlation.

  18. Temperature behavior of 12 wt.% U TRIGA fuel

    Energy Technology Data Exchange (ETDEWEB)

    Levine, S H; Geisler, G C; Totenbier, R E [Pennsylvania State University (United States)

    1974-07-01

    Stainless steel clad 12 wt % U TRIGA fuel elements have been used to refuel the Penn State University's Breazeale Reactor (PSBR). When 12 wt % U fuel containing nominally 55 gms of {sup 235}U per fuel element is substituted for the 8.5 wt % U fuel containing nominally 38 gms {sup 235}U, higher fuel temperatures were produced in the 12 wt % U fuel than in the 8.5 wt % U fuel at the same reactor powers. The higher fuel temperature can be related to the higher power densities in the 12 wt % U fuel. The power density is calculated to be 35% higher in the 12 wt % U fuel when 6 of these fuel elements are substituted for 8.5 wt % U fuel in the innermost ring, the B ring. Temperatures have been calculated for the 12 wt % U fuel in the above configuration for both steady state and pulse conditions, assuming a 35% higher fuel density in the 12 wt % U fuel and the results compare favorably with the experimental measurements. This is particularly true when the comparison is made with temperature data taken after exposing the new fuel elements to a series of pulses. These calculations and data will be presented at the meeting. (author)

  19. Chemical leaching of rapidly solidified Al-Si binary alloys

    International Nuclear Information System (INIS)

    Yamauchi, I.; Takahara, K.; Tanaka, T.; Matsubara, K.

    2005-01-01

    Various particulate precursors of Al 100-x Si x (x = 5-12) alloys were prepared by a rapid solidification process. The rapidly solidified structures of the precursors were examined by XRD, DSC and SEM. Most of Si atoms were dissolved into the α-Al(fcc) phase by rapid solidification though the solubility of Si in the α-Al phase is negligibly small in conventional solidification. In the case of 5 at.% Si alloy, a single α-Al phase was only formed. The amount of the primary Si phase increased with increase of Si content for the alloys beyond 8 at.% Si. Rapid solidification was effective to form super-saturated α-Al precursors. These precursors were chemically leached by using a basic solution (NaOH) or a hydrochloric acid (HCl) solution. All Al atoms were removed by a HCl solution as well as a NaOH solution. Granules of the Si phase were newly formed during leaching. The specific surface area was about 50-70 m 2 /g independent of Si content. The leaching behavior in both solutions was slightly different. In the case of a NaOH solution, the shape of the precursor often degenerated after leaching. On the other hand, it was retained after leaching by a HCl solution. Fine Si particles precipitated in the α-Al phase by annealing of as-rapidly solidified precursors at 773 K for 7.2 x 10 3 s. In this case, it was difficult to obtain any products by NaOH leaching, but a few of Si particles were obtained by HCl leaching. Precipitated Si particles were dissolved by the NaOH solution. The X-ray diffraction patterns of leached specimens showed broad lines of the Si phase and its lattice constant was slightly larger than that of the pure Si phase. The microstructures of the leached specimens were examined by transmission electron microscopy. It showed that the leached specimens had a skeletal structure composed of slightly elongated particles of the Si phase and quite fine pores. The particle size was about 30-50 nm. It was of comparable order with that evaluated by Scherer

  20. Experiment of solidifying photo sensitive polymer by using UV LED

    Science.gov (United States)

    Kang, Byoung Hun; Shin, Sung Yeol

    2008-11-01

    The development of Nano/Micro manufacturing technologies is growing rapidly and in the same manner, the investments in these areas are increasing. The applications of Nano/Micro technologies are spreading out to semiconductor production technology, biotechnology, environmental engineering, chemical engineering and aerospace. Especially, SLA is one of the most popular applications which is to manufacture 3D shaped microstructure by using UV laser and photo sensitive polymer. To make a high accuracy and precision shape of microstructures that are required from the diverse industrial fields, the information of interaction relationship between the photo resin and the light source is necessary for further research. Experiment of solidifying photo sensitive polymer by using UV LED is the topic of this paper and the purpose of this study is to find out what relationships do the reaction of the resin have in various wavelength, power of the light and time.

  1. Analysis list: Wt1 [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Wt1 Embryo,Kidney + mm9 http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Wt1.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/target/Wt1.5.tsv http://dbarchive.biosciencedbc.jp/kyush...u-u/mm9/target/Wt1.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Wt1.Embryo.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/mm9/colo/Wt1.Kidney.tsv http://dbarchive.biosciencedb...c.jp/kyushu-u/mm9/colo/Embryo.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/mm9/colo/Kidney.gml ...

  2. Microstructural Quantification of Rapidly Solidified Undercooled D2 Tool Steel

    Science.gov (United States)

    Valloton, J.; Herlach, D. M.; Henein, H.; Sediako, D.

    2017-10-01

    Rapid solidification of D2 tool steel is investigated experimentally using electromagnetic levitation (EML) under terrestrial and reduced gravity conditions and impulse atomization (IA), a drop tube type of apparatus. IA produces powders 300 to 1400 μm in size. This allows the investigation of a large range of cooling rates ( 100 to 10,000 K/s) with a single experiment. On the other hand, EML allows direct measurements of the thermal history, including primary and eutectic nucleation undercoolings, for samples 6 to 7 mm in diameter. The final microstructures at room temperature consist of retained supersaturated austenite surrounded by eutectic of austenite and M7C3 carbides. Rapid solidification effectively suppresses the formation of ferrite in IA, while a small amount of ferrite is detected in EML samples. High primary phase undercoolings and high cooling rates tend to refine the microstructure, which results in a better dispersion of the eutectic carbides. Evaluation of the cell spacing in EML and IA samples shows that the scale of the final microstructure is mainly governed by coarsening. Electron backscattered diffraction (EBSD) analysis of IA samples reveals that IA powders are polycrystalline, regardless of the solidification conditions. EBSD on EML samples reveals strong differences between the microstructure of droplets solidified on the ground and in microgravity conditions. While the former ones are polycrystalline with many different grains, the EML sample solidified in microgravity shows a strong texture with few much larger grains having twinning relationships. This indicates that fluid flow has a strong influence on grain refinement in this system.

  3. Structure fields in the solidifying cast iron roll

    Directory of Open Access Journals (Sweden)

    W.S. Wołczyński

    2010-01-01

    Full Text Available Some properties of the rolls depend on the ratio of columnar structure area to equiaxed structure area created during roll solidification. The transition is fundamental phenomenon that can be apply to characterize massive cast iron rolls produced by the casting house. As the first step of simulation, a temperature field for solidifying cast iron roll was created. The convection in the liquid is not comprised since in the first approximation, the convection does not influence the studied occurrence of the (columnar to equiaxed grains transition in the roll. The obtained temperature field allows to study the dynamics of its behavior observed in the middle of the mould thickness. This midpoint of the mould thickness was treated as an operating point for the transition. A full accumulation of the heat in the mould was postulated for the transition. Thus, a plateau at the curve was observed at the midpoint. The range of the plateau existence corresponded to the incubation period , that appeared before fully equiaxed grains formation. At the second step of simulation, behavior of the thermal gradients field was studied. Three ranges within the filed were visible: EC→EC→EC→EC→(tTECtt↔RERCtt↔a/ for the formation of columnar structure (the C – zone: ( and 0>>T&0>>=−>−=REREttGttG.The columnar structure formation was significantly slowed down during incubation period. It resulted from a competition between columnar growth and equiaxed growth expected at that period of time. The 0≈=−=RERCttGttG relationship was postulated to correspond well with the critical thermal gradient, known in the Hunt’s theory. A simulation was performed for the cast iron rolls solidifying as if in industrial condition. Since the incubation divides the roll into two zones: C and E; (the first with columnar structure and the second with fully equiaxed structure some experiments dealing with solidification were made on semi-industrial scale.

  4. WT1 isoform expression pattern in acute myeloid leukemia.

    Science.gov (United States)

    Luna, Irene; Such, Esperanza; Cervera, Jose; Barragán, Eva; Ibañez, Mariam; Gómez-Seguí, Inés; López-Pavía, María; Llop, Marta; Fuster, Oscar; Dolz, Sandra; Oltra, Silvestre; Alonso, Carmen; Vera, Belén; Lorenzo, Ignacio; Martínez-Cuadrón, David; Montesinos, Pau; Senent, M Leonor; Moscardó, Federico; Bolufer, Pascual; Sanz, Miguel A

    2013-12-01

    WT1 plays a dual role in leukemia development, probably due to an imbalance in the expression of the 4 main WT1 isoforms. We quantify their expression and evaluate them in a series of AML patients. Our data showed a predominant expression of isoform D in AML, although in a lower quantity than in normal CD34+ cells. We found a positive correlation between the total WT1 expression and A, B and C isoforms. The overexpression of WT1 in AML might be due to a relative increase in A, B and C isoforms, together with a relative decrease in isoform D expression. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Steady state creep during metastable phase transition in Al-16 wt% Ag and Al-16 wt% Ag-0.1 wt% Zr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Deaf, G.H.; Youssef, S.B.; Mahmoud, M.A. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics

    1998-08-16

    The early stages of decomposition of Guinier-Preston zones (G.P. zones) in Al-16 wt% Ag and Al-16 wt% Ag-0.1 wt% Zr alloys were investigated through creep measurements and electron microscopy observations. It was found that the strengthening and softening of the alloys has been achieved during the formation of metastable phases (G.P. zones and {gamma}`-phase) in the ageing temperature range (428 to 498 K). TEM investigations confirmed that the addition of zirconium to the Al-Ag alloy accelerates the formation and coarsening of the metastable phases. The mean values of activation energy of both alloys were found to be equal to that quoted for precipitate-dislocation interactions. (orig.) 23 refs.

  6. Rhodamine-WT dye losses in a mountain stream environment

    Science.gov (United States)

    Bencala, Kenneth E.; Rathburn, Ronald E.; Jackman, Alan P.; Kennedy, Vance C.; Zellweger, Gary W.; Avanzino, Ronald J.

    1983-01-01

    A significant fraction of rhodamine WT dye was lost during a short term multitracer injection experiment in a mountain stream environment. The conservative anion chloride and the sorbing cation lithium were concurrently injected. In-stream rhodamine WT concentrations were as low as 45 percent of that expected, based on chloride data. Concentration data were available from shallow‘wells’dug near the stream course and from a seep of suspected return flow. Both rhodamine WT dye and lithium were nonconservative with respect to the conservative chloride, with rhodamine WT dye closely following the behavior of the sorbing lithium.Nonsorption and sorption mechanisms for rhodamine WT loss in a mountain stream were evaluated in laboratory experiments. Experiments evaluating nonsorption losses indicated minimal losses by such mechanisms. Laboratory experiments using sand and gravel size streambed sediments show an appreciable capacity for rhodamine WT sorption.The detection of tracers in the shallow wells and seep indicates interaction between the stream and the flow in the surrounding subsurface, intergravel water, system. The injected tracers had ample opportunity for intimate contact with materials shown in the laboratory experiments to be potentially sorptive. It is suggested that in the study stream system, interaction with streambed gravel was a significant mechanism for the attenuation of rhodamine WT dye (relative to chloride).

  7. Solidified structure of Al-Pb-Cu alloys

    International Nuclear Information System (INIS)

    Ikeda, Tetsuyuki; Nishi, Seiki; Kumeuchi, Hiroyuki; Tatsuta, Yoshinori.

    1986-01-01

    Al-Pb-Cu alloys were cast into bars or plates in different two metal mold casting processes in order to suppress gravity segregation of Pb and to achieve homogeneous dispersion of Pb phase in the alloys. Solidified structures were analyzed by a video-pattern-analyzer. Plate castings 15 to 20 mm in thickness of Al-Pb-1 % Cu alloy containing Pb up to 5 % in which Pb phase particles up to 10 μm disperse are achieved through water cooled metal mold casting. The plates up to 5 mm in thickness containing Pb as much as 8 to 10 % cast in this process have dispersed Pb particles up to 5 μm in diameter in the surface layer. Al-8 % Pb-1 % Cu alloy bars 40 mm in diameter and 180 mm in height in which gravity segregation of Pb is prevented can be cast by movable and water sprayed metal mold casting at casting temperature 920 deg C and mold moving speed 1.0 mm/s. Pb phase particles 10 μm in mean size are dispersed in the bars. (author)

  8. Characteristics of solidified products containing radioactive molten salt waste.

    Science.gov (United States)

    Park, Hwan-Seo; Kim, In-Tae; Cho, Yong-Zun; Eun, Hee-Chul; Kim, Joon-Hyung

    2007-11-01

    The molten salt waste from a pyroprocess to recover uranium and transuranic elements is one of the problematic radioactive wastes to be solidified into a durable wasteform for its final disposal. By using a novel method, named as the GRSS (gel-route stabilization/solidification) method, a molten salt waste was treated to produce a unique wasteform. A borosilicate glass as a chemical binder dissolves the silicate compounds in the gel products to produce one amorphous phase while most of the phosphates are encapsulated by the vitrified phase. Also, Cs in the gel product is preferentially situated in the silicate phase, and it is vitrified into a glassy phase after a heat treatment. The Sr-containing phase is mainly phosphate compounds and encapsulated by the glassy phase. These phenomena could be identified by the static and dynamic leaching test that revealed a high leach resistance of radionuclides. The leach rates were about 10(-3) - 10(-2) g/m2 x day for Cs and 10(-4) - 10(-3) g/m2 x day for Sr, and the leached fractions of them were predicted to be 0.89% and 0.39% at 900 days, respectively. This paper describes the characteristics of a unique wasteform containing a molten salt waste and provides important information on a newly developed immobilization technology for salt wastes, the GRSS method.

  9. Site suitability criteria for solidified high level waste repositories

    International Nuclear Information System (INIS)

    Heckman, R.A.; Holdsworth, T.; Isherwood, D.; Towse, D.F.; Dayem, N.L.

    1979-01-01

    The NRC is developing a framework of regulations, criteria, and standards. Lawrence Livermore Laboratory provides broad technical support to the NRC for developing this regulatory framework, part of which involves site suitability criteria for solidified high-level wastes (SHLW). Both the regulatory framework and the technical base on which it rests have evolved in time. This document is the second report of the technical support project. It was issued as a draft working paper for a programmatic review held at LLL from August 16 to 18, 1977. It was printed and distributed solely as a briefing document on preliminary methodology and initial findings for the purpose of critical review by those in attendance. These briefing documents are being reprinted now in their original formats as UCID-series reports for the sake of the historical record. Analysis results have evolved as both the models and data base have changed. As a result, the methodology, models, and data base in this document are severely outmoded

  10. A new technology for concentrating and solidifying liquid LLRW

    Energy Technology Data Exchange (ETDEWEB)

    Newell, N. [TMC, Inc., Portland, OR (United States); Osborn, M.W.; Carey, C.C. [Oregon Health Sciences Univ., Portland, OR (United States)] [and others

    1995-12-31

    One of the unsolved problem areas of low level radioactive waste management is the radiolabeled material generated by life sciences research and clinical diagnostics. In hundreds of academic, biotechnology, and pharmaceutical institutions, there exists large amounts of both aqueous and organic solutions containing radioactively labeled nucleic acids, proteins, peptides, and their monomeric components. We have invented a generic slurry capable of binding all these compounds, thus making it possible to concentrate and solidify the radioactive molecules into a very small and lightweight material. The slurry can be contained in both large and small disposal plastic devices designed for the size of any particular operation. The savings in disposal costs and convenience of this procedure is a very attractive alternative to the present methods of long and short term storage. Additionally, the slurry can remove radiolabeled biological compounds from organic solvents, thus solving the major problem of {open_quotes}mixed{close_quotes} waste. We are now proceeding with the field application stage for the testing of these devices and anticipate widespread use of the process. We also are exploring the use of the slurry on other types of liquid low level radioactive waste.

  11. Solidified self-nanoemulsifying formulation for oral delivery of combinatorial therapeutic regimen

    DEFF Research Database (Denmark)

    Jain, Amit K; Thanki, Kaushik; Jain, Sanyog

    2014-01-01

    PURPOSE: The present work reports rationalized development and characterization of solidified self-nanoemulsifying drug delivery system for oral delivery of combinatorial (tamoxifen and quercetin) therapeutic regimen. METHODS: Suitable oil for the preparation of liquid SNEDDS was selected based...

  12. Welding and Weldability of Directionally Solidified Single Crystal Nickel-Base Superalloys

    Energy Technology Data Exchange (ETDEWEB)

    Vitek, J M; David, S A; Reed, R W; Burke, M A; Fitzgerald, T J

    1997-09-01

    Nickel-base superalloys are used extensively in high-temperature service applications, and in particular, in components of turbine engines. To improve high-temperature creep properties, these alloys are often used in the directionally-solidified or single-crystal form. The objective of this CRADA project was to investigate the weldability of both experimental and commercial nickel-base superalloys in polycrystalline, directionally-solidified, and single-crystal forms.

  13. The stored energy in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg

    International Nuclear Information System (INIS)

    Li, X.F.; Dong, A.P.; Wang, L.T.; Yu, Z.; Meng, L.

    2011-01-01

    Research highlights: → The crystal orientation in processed Cu-0.4 wt.%Cr-0.12 wt.%Zr-0.02 wt.%Si-0.05 wt.%Mg is deviating from the as-cast specimens and microstrain of the alloy is gradually increasing as the draw ratio rising before η ≤ 6.7. → The dynamic recovery has taken place as 6.7 texture is formed with the draw ratio rising. Meanwhile, the stored energy also increases with the draw ratio rising and a peak is reached with draw ratio of 6.7. The release of stored energy is primarily due to the decrease of dislocation density. The flow stress estimated from the stored energy has a similar variation trend with the measured data with a stress difference ∼20 to 120 MPa. The main strengthening effect is attributed to dislocation mechanism.

  14. Effect of superimposed low frequency oscillations on the static creep behaviour of Al-1 wt%Si and Al-1 wt%Si-0.1 wt%Zr-0.1 wt%Ti alloys

    Energy Technology Data Exchange (ETDEWEB)

    Beshai, M.H.N. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Deaf, G.H. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Abd El Khalek, A.M. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Graiss, G. [Ain Shams Univ., Cairo (Egypt). Dept. of Physics; Kenawy, M.A. [Physics Dept., University Coll. for Women, Ain Shams Univ., Cairo (Egypt)

    1997-05-16

    Torsional oscillations of increasing frequencies with constant torsional strain amplitude, {theta}, of 3.1 x 10{sup -4} were superimposed on wires of Al-1 wt% Si and Al-1 wt% Si-0.1 wt% Zr-0.1 wt% Ti alloys, while being crept under constant stress (52.3 MPa) and different testing temperatures. It was found that increasing the frequency of oscillations resulted in an increase of both transient and steady state creep. In the transient stage, while the exponent n is increasing with frequency v, the parameter {beta} decreases. Zirconium and titanium addition generally reduced the rate of creep. A value of 20 kJ/mol was found for the activation energy of the mechanism operating in the transient and steady state stages which was ascribed as being due to dislocation intersection. (orig.)

  15. Macrosegregation Due to Convection in Al-19Cu Alloy Directionally Solidified Through an Abrupt Expansion in Cross-Section: A Comparison with Al-7Si

    Science.gov (United States)

    Ghods, M.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2017-10-01

    Hypoeutectic Al-19 wt.% Cu alloys were directionally solidified at two different growth speeds in cylindrical molds that featured an abrupt increase in cross-section, from 3.2 to 9.5 mm in diameter. The effects of thermosolutal convection and shrinkage flow induced by the cross-section change on macrosegregation were investigated. Dendrite clustering and extensive radial macrosegregation were seen, particularly in the larger cross-section after expansion. Negative longitudinal macrosegregation right after the cross-section increase was observed; the extent of macrosegregation, however, decreases with increasing growth speed. Both thermal and flow effects due to cross-section change were seen to influence the radial macrosegregation immediately before, and after the expansion. Radial macrosegregation pattern was found to be changing as the mushy zone enters the larger cross-section region above the cross-section change where the solidification is in its unsteady state. The effect of the solutal expansion coefficient on macrosegregation was studied by comparing the degree of thermosolutal convection in Al-19 wt.% Cu with a previous study in which we investigated Al-7 wt.% Si. A two-dimensional model accounting for both shrinkage and thermosolutal convection was used to simulate the resulting steepling, as well as the axial and radial macrosegregation. The experimentally observed macrosegregation associated with the expansion during directional solidification is well predicted by the numerical simulations.

  16. Effect of thermo-mechanical processing on microstructure and mechanical properties of U - Nb - Zr alloys: Part 2 - U - 3 wt % Nb - 9 wt % Zr and U - 9 wt% Nb - 3 wt% Zr

    Science.gov (United States)

    Morais, Nathanael Wagner Sales; Lopes, Denise Adorno; Schön, Cláudio Geraldo

    2018-04-01

    The present work is the second and final part of an extended investigation on Usbnd Nb - Zr alloys. It investigates the effect of mechanical processing routes on microstructure of alloys U - 3 wt % Nb - 9 wt % Zr and U - 9 wt% Nb - 3 wt% Zr, through X-ray diffraction and scanning electron microscopy, completing the investigation, which started with alloy U - 6 wt% Nb - 6 wt% Zr in part 1. Mechanical properties are determined using microhardness and bending tests and correlated with the developed microstructures. The results show that processing sequence, in particular the inclusion of a 1000 °C heat treatment step, affects significantly the microstructure and mechanical properties of these alloys alloy in different ways. Microstructural characterization shows that both alloys present significant volume fraction of precipitates of a body-centered cubic (BCC) γ-Nb-Zr rich phase in addition the uranium-rich matrix. Bending tests show that sample ductility does not correlate necessarily with hardness and that the key factor appears to be the amount of the γ-Nb-Zr precipitates, which controls the matrix microstructure. Samples with a monoclinic α″ cellular microstructure and/or with the tetragonally-distorted BCC phase (γ0), although not strictly ductile, showed the largest allowed strains-before-break and complete elastic recovery of the broken pieces, pointing out to the macroscopic observation of superelasticity.

  17. Containment of solidified liquid hazardous waste in domal salt

    International Nuclear Information System (INIS)

    Domenico, P.A.; Lerman, A.

    1992-01-01

    In recent years, the solidification of hazardous liquid waste has become a viable option in waste management. The solidification process results in an increased volume but more stable waste form that must be disposed of or stored in a dry environment. An environment of choice in south central Texas is domal salt. The salt dome currently under investigation has a water content of 0.002 percent by weight and a permeability less than one nanodarcy. A question that must be addressed is whether a salt dome has a particular set of attributes that will prevent the release of contaminants to the environment. From a regulatory perspective, a ''no migration'' petition must be approved by the U.S.E.P.A. for the containment facility. By ''no migration'' it is implied that the waste must be contained for 10,000 years. A demonstration that this condition will be met will require model calculations and such models must be based on the physical and chemical characteristics of the waste form and the geologic environment. In particular, the models must address the rate of brine infiltration into the caverns, providing information on how fast an immobile solid waste form could convert to a more mobile liquid state. Additionally, the potential for migration by both diffusion and advection is of concern. Lastly, given a partially saturated cavern, the question of how far gaseous waste will be transported over the 10,000 year containment period must also be addressed. Results indicate that the containment capabilities of domal salt are exceptional. A nominal volume of brine will seep into the cavern and most voids between the injected solidified waste pellets will remain unsaturated. Very small quantities of hazardous constituents will be leached from the waste pellets

  18. Measurements of Mercury Released from Solidified/Stabilized Waste Forms

    International Nuclear Information System (INIS)

    Mattus, C.H.

    2001-01-01

    This report covers work performed during FY 1999-2000 in support of treatment demonstrations conducted for the Mercury Working Group of the U.S. Department of Energy (DOE) Mixed Waste Focus Area. In order to comply with the requirements of the Resource Conservation and Recovery Act, as implemented by the U.S. Environmental Protection Agency (EPA), DOE must use one of these procedures for wastes containing mercury at levels above 260 ppm: a retorting/roasting treatment or an incineration treatment (if the wastes also contain organics). The recovered radioactively contaminated mercury must then be treated by an amalgamation process prior to disposal. The DOE Mixed Waste Focus Area and Mercury Working Group are working with the EPA to determine if some alternative processes could treat these types of waste directly, thereby avoiding for DOE the costly recovery step. They sponsored a demonstration in which commercial vendors applied their technologies for the treatment of two contaminated waste soils from Brookhaven National Laboratory. Each soil was contaminated with ∼4500 ppm mercury; however, one soil had as a major radioelement americium-241, while the other contained mostly europium-152. The project described in this report addressed the need for data on the mercury vapor released by the solidified/stabilized mixed low-level mercury wastes generated during these demonstrations as well as the comparison between the untreated and treated soils. A related work began in FY 1998, with the measurement of the mercury released by amalgamated mercury, and the results were reported in ORNL/TM-13728. Four treatments were performed on these soils. The baseline was obtained by thermal treatment performed by SepraDyne Corp., and three forms of solidification/stabilization were employed: one using sulfur polymer cement (Brookhaven National Laboratory), one using portland cement [Allied Technology Group (ATG)], and a third using proprietary additives (Nuclear Fuel Services)

  19. Acoustic emission from a solidifying aluminum-lithium alloy

    Science.gov (United States)

    Henkel, D. P.; Wood, J. D.

    1992-01-01

    Physical phenomena associated with the solidification of an AA2090 Al-Li alloy have been characterized by AE methods. Repeatable patterns of AE activity as a function of solidification time are recorded and explained for ultrahigh-purity (UHP) aluminum and an Al-4.7 wt pct Cu binary alloy, in addition to the AA2090 Al-Li alloy, by the complementary utilization of thermal, AE, and metallographic methods. One result shows that the solidification of UHP aluminum produces one discrete period of high AE activity as the last 10 percent of solid forms.

  20. Investigation on microstructure characterization and property of rapidly solidified Mg-Zn-Ca-Ce-La alloys

    Energy Technology Data Exchange (ETDEWEB)

    Zhou Tao, E-mail: tzhou1118@163.com [College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Chen Zhenhua, E-mail: chenzhenhua45@hotmail.com [College of Material Science and Engineering, Hunan University, Changsha 410082 (China); Yang Mingbo, E-mail: yangmingbo@cqit.edu.cn [College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Hu Jianjun, E-mail: hujj@qq.com [College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China); Xia Hua, E-mail: xiahua@cqut.edu.cn [College of Material Science and Engineering, Chongqing University of Technology, Chongqing 400054 (China)

    2012-01-15

    Rapidly solidified (RS) Mg-Zn-Ca-Ce-La (wt.%) alloys have been produced via atomizing the alloy melt and subsequent splat-quenching on the water-cooled copper twin-rollers in the form of flakes. Microstructure characterization, phase compositions and thermal stability of the alloys have been systematically investigated. The results showed that with addition of RE (Ce and La) to the Mg-6Zn-5Ca alloy, the stable intermetallic compounds i.e. the Mg{sub x}Zn{sub y}RE{sub z} phase with a few Ca (about 3 at.%), shortened as the T Prime phase, were formed at the expense of the binary Mg-Zn and Ca{sub 2}Mg{sub 6}Zn{sub 3} phases, which was possibly beneficial to the enhanced thermal stability of the alloy. In the Mg-6Zn-5Ca-3Ce-0.5La alloy, the composition of the T Prime phase in the grain interior was different from that at the grain boundaries, in which the segregation of the La elements was found, and the atomic percentage ratio of Zn to Ce in the T Prime phase within the grains was close to 2. Moreover, the stable Mg{sub 2}Ca phases were detected around the T Prime phases at the grain boundaries in the alloy. - Research Highlights: Black-Right-Pointing-Pointer The phase constitution of RS Mg-6Zn-5Ca alloy can be improved by RE additions. Black-Right-Pointing-Pointer In the Mg-Zn-Ca-Ce-La alloys, the Mg{sub x}Zn{sub y}RE{sub z} phase with a few Ca (T Prime phase) is formed. Black-Right-Pointing-Pointer The formation of the T Prime phase leads to the loss of the Mg-Zn and Ca{sub 2}Mg{sub 6}Zn{sub 3} phases. Black-Right-Pointing-Pointer The composition of the T Prime phase differs from the grain interior to the grain boundary.

  1. Microstructure and mechanical properties of a novel rapidly solidified, high-temperature Al-alloy

    Energy Technology Data Exchange (ETDEWEB)

    Overman, N.R., E-mail: Nicole.Overman@pnnl.gov [Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); Mathaudhu, S.N. [Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States); University of California, Riverside, 3401 Watkins Dr., Riverside, CA 92521 (United States); Choi, J.P.; Roosendaal, T.J.; Pitman, S. [Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 (United States)

    2016-02-15

    Rapid solidification (RS) processing, as a production method, offers a variety of unique properties based on far-from-equilibrium microstructures obtained through rapid cooling rates. In this study, we seek to investigate the microstructures and properties of a novel Al-alloy specifically designed for high temperature mechanical stability. Synthesis of, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} (wt.%), was performed by two approaches: rotating cup atomization (“shot”) and melt spinning (“flake”). These methods were chosen because of their ability to produce alloys with tailored microstructures due to their inherent differences in cooling rate. The as-solidified precursor materials were microstructurally characterized with electron microscopy. The results show that the higher cooling rate flake material exhibited the formation of nanocrystalline regions as well additional phase morphologies not seen in the shot material. Secondary dendritic branching in the flake material was on the order of 0.1–0.25 μm whereas branching in the shot material was 0.5–1.0 μm. Consolidated and extruded material from both precursor materials was mechanically evaluated at both ambient and high (300 °C) temperature. The consolidated RS flake material is shown to exhibit higher strengths than the shot material. The ultimate tensile strength of the melt spun flake was reported as 544.2 MPa at room temperature and 298.0 MPa at 300 °C. These results forecast the ability to design alloys and processing approaches with unique non-equilibrium microstructures with robust mechanical properties at elevated temperatures. - Highlights: • A novel alloy, AlFe{sub 11.4}Si{sub 1.8}V{sub 1.6}Mn{sub 0.9} was fabricated by rapid solidification. • Room temperature yield strength exceeded 500 MPa. • Elevated temperature (300 °C) yield strength exceeded 275 MPa. • Forging, after extrusion of the alloy resulted in microstructural coarsening. • Decreased strength and ductility was

  2. Effects of Mo on microstructure of as-cast 28 wt.% Cr–2.6 wt.% C–(0–10) wt.% Mo irons

    Energy Technology Data Exchange (ETDEWEB)

    Imurai, S. [Department of Physics and Materials Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thanachayanont, C.; Pearce, J.T.H. [National Metal and Materials Technology Center, Pathumthani 12120 (Thailand); Tsuda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Chairuangsri, T., E-mail: tchairuangsri@gmail.com [Department of Industrial Chemistry, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2014-04-01

    Microstructures of as-cast 28 wt.% Cr–2.6 wt.% C irons containing (0–10) wt.% Mo with the Cr/C ratio of about 10 were studied and related to hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the iron with about 10 wt.% Mo was eutectic/peritectic, whereas the others with less Mo content were hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. Mo addition promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C. At 1 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3}, M{sub 23}C{sub 6} and M{sub 6}C were observed. M{sub 23}C{sub 6} existed as a transition zone between eutectic M{sub 7}C{sub 3} and M{sub 6}C, indicating a carbide transition as M{sub 7}C{sub 3}(M{sub 2.3}C) → M{sub 23}C{sub 6}(M{sub 3.8}C) → M{sub 6}C. At 6 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3} and M{sub 23}C{sub 6} were observed together with fine cellular/lamellar M{sub 6}C aggregates. In the iron with 10 wt.% Mo, only eutectic/peritectic M{sub 23}C{sub 6} and M{sub 6}C were found without M{sub 7}C{sub 3}. Mo distribution to all carbides has been determined to be increased from ca. 0.4 to 0.7 in mass fraction as the Mo content in the irons was increased. On the other hand, Cr distribution to all carbides is quite constant as ca. 0.6 in mass fraction. Mo addition increased Vickers macro-hardness of the irons from 495 up to 674 HV{sub 30}. High Mo content as solid-solution in the matrix and the formation of M{sub 6}C or M{sub 23}C{sub 6} aggregates were the main reasons for hardness increase, indicating potentially improved wear performance of the irons with Mo addition. - Highlights: • Mo promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C in the irons with Cr/C ratio of about 10

  3. Effects of W on microstructure of as-cast 28 wt.%Cr–2.6 wt.%C–(0–10)wt.%W irons

    Energy Technology Data Exchange (ETDEWEB)

    Imurai, S. [Department of Physics and Materials Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thanachayanont, C.; Pearce, J.T.H. [National Metal and Materials Technology Center, Pathumthani 12120 (Thailand); Tsuda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Chairuangsri, T., E-mail: tchairuangsri@gmail.com [Department of Industrial Chemistry, Chiang Mai University, Chiang Mai 50200 (Thailand)

    2015-01-15

    Microstructures of as-cast 28 wt.%Cr–2.6 wt.%C irons containing (0–10)wt.%W with the Cr/C ratio about 10 were studied and related to their hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the irons with 1 to 10 wt.%W addition was hypereutectic containing large primary M{sub 7}C{sub 3}, whereas the reference iron without W addition was hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. The volume fractions of primary M{sub 7}C{sub 3} and the total carbides increased, but that of eutectic carbides decreased with increasing the W content of the irons. W addition promoted the formation of W-rich M{sub 7}C{sub 3}, M{sub 6}C and M{sub 23}C{sub 6}. At about 4 wt.%W, two eutectic carbides including M{sub 7}C{sub 3} and M{sub 6}C were observed together with primary M{sub 7}C{sub 3}. At 10 wt.%W, multiple carbides including primary M{sub 7}C{sub 3}, fish-bone M{sub 23}C{sub 6}, and M{sub 6}C were observed. M{sub x}C where x = 3 or less has not been found due possibly to the high M/C ratio in the studied irons. W distribution to all carbides has been determined increasing from ca. 0.3 to 0.8 in mass fraction as the W content in the irons was increased. W addition led to an increase in Vickers macro-hardness of the irons up to 671 kgf/(mm){sup 2} (HV30/15) obtained from the iron with 10 wt.%W. The formation of primary M{sub 7}C{sub 3} and aggregates of M{sub 6}C and M{sub 23}C{sub 6} were the main reasons for hardness increase, indicating potentially improved wear performance of the as-cast irons with W addition. - Highlights: • W addition at 1 up to 10 wt.%W to Fe–28Cr–2.6C produced “hypereutectic” structure. • W addition promoted the formation of W-rich M{sub 7}C{sub 3}, M{sub 6}C and M

  4. The role of Ag precipitates in Cu-12 wt% Ag

    Energy Technology Data Exchange (ETDEWEB)

    Yao, D.W.; Song, L.N. [Department of Materials Science and Engineering, Zhejiang University, Zheda Road No.38, Hangzhou, Zhejiang 310027 (China); Dong, A.P.; Wang, L.T. [China Railway Construction Electrification Bureau Group Co.,Ltd., Beijing 100036 (China); Zhang, L. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Meng, L., E-mail: mengliang@zju.edu.cn [Department of Materials Science and Engineering, Zhejiang University, Zheda Road No.38, Hangzhou, Zhejiang 310027 (China)

    2012-12-15

    The Cu-12 wt% Ag was prepared to investigate the role of Ag precipitates on the properties of the alloy. Two kinds of heat treatment procedures were adopted to produce different amount of Ag precipitates in the Cu-12 wt% Ag. The microstructure of Ag precipitates was systematically observed by optical microscopy and electron microscopy. The Cu-12 wt% Ag with more Ag precipitates exhibits higher strength and lower electrical conductivity. More Ag precipitates results in more phase interface and less Ag atoms dissolved in Cu matrix. By comparing the strengthening effect and electron scattering effect of phase interface and dissolved Ag atoms, it is conclude that the interface between Cu matrix and Ag precipitates could significantly block dislocation movement and enhance electron scattering in Cu-Ag alloys.

  5. Analysis of cement solidified product and ash samples and preparation of a reference material

    International Nuclear Information System (INIS)

    Ishimori, Ken-ichiro; Haraga, Tomoko; Shimada, Asako; Kameo, Yutaka; Takahashi, Kuniaki

    2010-08-01

    Simple and rapid analytical methods for radionuclides in low-level radioactive waste have been developed by the present authors. The methods were applied to simulated solidified products and actual metal wastes to confirm their usefulness. The results were summarized as analytical guide lines. In the present work, cement solidified product and ash waste were analyzed followed by the analytical guide lines and subjects were picked up and solved for the application of the analytical guide lines to these wastes. Pulverization and homogenization method for ash waste was improved to prevent a contamination since the radioactivity concentrations of the ash samples were relatively high. Pre-treatment method was altered for the cement solidified product and ash samples taking account for their high concentration of Ca. Newly, an analytical method was also developed to measure 129 I with a dynamic reaction cell inductively coupled plasma mass spectrometer. In the analytical test based on the improved guide lines, gamma-ray emitting nuclides, 60 Co and 137 Cs, were measured to estimate the radioactivity of the other alpha and beta-ray emitting nuclides. The radionuclides assumed detectable, 3 H, 14 C, 36 Cl, 63 Ni, 90 Sr, and alpha-ray emitting nuclides, were analyzed with the improved analytical guide lines and their applicability for cement solidified product and ash samples were confirmed. Additionally a cement solidified product sample was evaluated in terms of the homogeneity and the radioactivity concentrations in order to prepare a reference material for radiochemical analysis. (author)

  6. On confirmation of abandonment of imported waste (glass solidified bodies) outside business places

    International Nuclear Information System (INIS)

    1996-01-01

    Electric power companies entrust the reprocessing of spent fuel generated from nuclear power stations to COGEMA in France, and in April, 1995, 28 high level radioactive wastes (glass solidified bodies) generated by the reprocessing were returned. When these glass solidified wastes are abandoned in the waste management facility of Japan Nuclear Fuel Service Co., it was decided to receive the confirmation of the prime minister on the measures based on the relevant law. Four electric power companies submitted the application and the explanation paper. As to the contents of the glass solidified wastes, the technical inspection was carried out by Bureau Veritas. Considering that this import of glass solidified wastes is the first in Japan, Science and Technology Agency carried out the measurement of all 28 wastes. The results are reported. It was confirmed that the measures for the abandonment taken by four electric power companies conform to the stipulation. The contents of the confirmation are reported in the order of the stipulation. These wastes were solidified with borosilicate glass in 5 mm thick stainless steel vessels, and the welding was done properly. (K.I.)

  7. TRIGA high wt -% LEU fuel development program. Final report

    International Nuclear Information System (INIS)

    West, G.B.

    1980-07-01

    The principal purpose of this work was to investigate the characteristics of TRIGA fuel where the contained U-235 was in a relatively high weight percent (wt %) of LEU (low enriched uranium - enrichment of less than 20%) rather than a relatively low weight percent of HEU (high enriched uranium). Fuel with up to 45 wt % U was fabricated and found to be acceptable after metallurgical examinations, fission product retention tests and physical property examinations. Design and safety analysis studies also indicated acceptable prompt negative temperature coefficient and core lifetime characteristics for these fuels

  8. Experimental evaluation of cement materials for solidifying sodium nitrate

    International Nuclear Information System (INIS)

    Sasaki, Tadashi; Numata, Mamoru; Suzuki, Yasuhiro; Kubo, Yoshikazu

    2003-03-01

    Low-level liquid waste containing sodium nitrate is planned to be transformed to salt block by evaporation with sodium borate in the Low-level Waste Treatment Facility (LWTF), then salt block will be stored temporally. It should be important to investigate the method how to treat these liquid waste suitable to final disposal criteria that will be settled in future. Cement solidification is one of promising candidates because it has been achieved as the solidification material for the shallow land disposal. The research was conducted to evaluate applicability of various cement materials to solidification of sodium nitrate. The following cements were tested. Ordinary Portland Cement (OPC). Portland Blast-furnace Slag Cement; C type (PBFSC). Alkali Activated Slag Cement (AASC, supplied by JGC). The test results are as follows; (1) AASC is characterized by a high sodium nitrate loading (-70 wt%) compared with other types of cement material. High fluidity of the cement paste, high strength after solidification, and minimization of free water on the cement paste are achieved under all test conditions. (2) OOPC and PBFSC produced free water on the cement paste in the early days and delayed the hardening period. 3 or more days are required to harden evan with 30 wt% content of sodium nitrate. (3) Though PBFSC contains blast furnace slag similar to AASC, there is no advantage prior to OPC. To design an ideal cement conditioning system for sodium nitrate liquid waste in the LWTF, the further studies are necessary such as the simulated waste test, Kd test, pilot test, and layout design. (author)

  9. Mechanical alloying and sitering of TI - 10WT.% MG powders

    CSIR Research Space (South Africa)

    Machio, Christopher N

    2009-06-01

    Full Text Available A Ti-10wt.%Mg powder alloy has been produced by mechanical alloying. Elemental powders of Ti and Mg were ball milled in a Zoz-Simoloyer CM01 for 16 and 20 hours under argon. Mechanical alloying was followed by XRD, SEM and particle size analysis...

  10. Nanoscale microstructure effects on hydrogen behavior in rapidly solidified aluminum alloys

    Energy Technology Data Exchange (ETDEWEB)

    Tashlykova-Bushkevich, Iya I. [Belarusian State University of Informatics and Radioelectronics, Minsk (Belarus)

    2015-12-31

    The present work summarizes recent progress in the investigation of nanoscale microstructure effects on hydrogen behavior in rapidly solidified aluminum alloys foils produced at exceptionally high cooling rates. We focus here on the potential of modification of hydrogen desorption kinetics in respect to weak and strong trapping sites that could serve as hydrogen sinks in Al materials. It is shown that it is important to elucidate the surface microstructure of the Al alloy foils at the submicrometer scale because rapidly solidified microstructural features affect hydrogen trapping at nanostructured defects. We discuss the profound influence of solute atoms on hydrogen−lattice defect interactions in the alloys. with emphasis on role of vacancies in hydrogen evolution; both rapidly solidified pure Al and conventionally processed aluminum samples are considered.

  11. TEM Characterization and Properties of Cu-1 wt.% TiB2 Nanocomposite Prepared by Rapid Solidification and Subsequent Heat Treatment

    Directory of Open Access Journals (Sweden)

    M. Sobhani

    2012-12-01

    Full Text Available Copper matrix composite reinforced by 1wt.% TiB2 particles was prepared using in situ reaction of Cu-1.4wt.% Ti and Cu-0.7wt.% B by rapid solidification and subsequent heat treatment for 1-20 hrs at 900ºC. High-resolution transmission electron microscopy (HRTEM characterization showed that primary TiB2 particles were formed in liquid copper. Heat treatment of as-solidified samples led to the formation of secondary TiB2 particles via spinodal decomposition of titanium-rich zone inside the grains. Mechanical properties (after 50% reduction in area as well as electrical conductivity of composite were evaluated after heat treatment and were compared with those of pure copper. The results indicated that, due to the formation of secondary TiB2 particles in the matrix, electrical conductivity increased along with hardness up to 10 hrs of heat treatment and reached 65% IACS and 155 HV, respectively. Moreover, the maximum ultimate (i.e. 580 MPa and yield (i.e. 555 MPa strengths of composite were achieved at this time.

  12. A Study on Factors Affecting Strength of Solidified Peat through XRD and FESEM Analysis

    Science.gov (United States)

    Rahman, J. A.; Napia, A. M. A.; Nazri, M. A. A.; Mohamed, R. M. S. R.; Al-Geethi, A. S.

    2018-04-01

    Peat is soft soil that often causes multiple problems to construction. Peat has low shear strength and high deformation characteristics. Thus, peat soil needs to be stabilized or treated. Study on peat stabilization has been conducted for decades with various admixtures and mixing formulations. This project intends to provide an overview of the solidification of peat soil and the factors that affecting the strength of solidified peat soil. Three types of peats which are fabric, hemic and sapric were used in this study to understand the differences on the effect. The understanding of the factors affecting strength of solidified peat in this study is limited to XRD and FESEM analysis only. Peat samples were collected at Pontian, Johor and Parit Raja, Johor. Peat soil was solidified using fly ash, bottom ash and Portland cement with two mixing formulation following literature review. The solidified peat were cured for 7 days, 14 days, 28 days and 56 days. All samples were tested using Unconfined Compressive Strength Test (UCS), X-ray diffraction (XRD) and Field Emission Scanning Electron Microscope (FESEM). The compressive strength test of solidified peat had shown consistently increase of sheer strength, qu for Mixing 1 while decrease of its compressive strength value for Mixing 2. All samples were tested and compared for each curing days. Through XRD, it is found that all solidified peat are dominated with pargasite and richterite. The highest qu is Fabric Mixing 1(FM1) with the value of 105.94 kPa. This sample were proven contain pargasite. Samples with high qu were observed to be having fly ash and bottom ash bound together with the help of pargasite. Sample with decreasing strength showed less amount of pargasite in it. In can be concluded that XRD and FESEM findings are in line with UCS values.

  13. Microstructure and mechanical properties of an Al–Mg alloy solidified under high pressures

    International Nuclear Information System (INIS)

    Jie, J.C.; Zou, C.M.; Brosh, E.; Wang, H.W.; Wei, Z.J.; Li, T.J.

    2013-01-01

    Highlights: •Al–42.2Mg alloy was solidified under pressures of 1, 2, and 3 GPa and the microstructure analyzed. •A thermodynamic calculation of the Al–Mg phase diagram at high pressures was performed. •The phase content changes from predominantly γ-Al 12 Mg 17 at 1 GPa to FCC solid solution at 3 GPa. •The β-Al 3 Mg 2 is predicted to remain stable at low temperatures but is not observed. •The alloy solidified at high pressure has remarkably enhanced ultimate tensile strength. -- Abstract: Phase formation, the microstructure and its evolution, and the mechanical properties of an Al–42.2 at.% Mg alloy solidified under high pressures were investigated. After solidification at pressures of 1 GPa and 2 GPa, the main phase is the γ phase, richer in Al than in equilibrium condition. When the pressure is further increased to 3 GPa, the main phase is the supersaturated Al(Mg) solid solution with Mg solubility up to 41.6 at.%. Unlike in similar alloys solidified at ambient pressure, the β phase does not appear. Calculated high-pressure phase diagrams of the Al–Mg system show that although the stability range of the β phase is diminished with pressure, it is still thermodynamically stable at room temperature. Hence, the disappearance of the β phase is interpreted as kinetic suppression, due to the slow diffusion rate at high pressures, which inhibits solid–solid reactions. The Al–42.2 at.% Mg alloy solidified under 3 GPa has remarkably enhanced ultimate tensile strength compared to the alloy solidified under normal atmospheric pressure

  14. Measurement of the leaching rate of radionuclide 134Cs from the solidified radioactive sources in Portland cement mixed with microsilica and barite matrixes

    International Nuclear Information System (INIS)

    Shaaban, Ismail; Assi, Nasim

    2011-01-01

    Portland cement was mixed with radionuclide 134 Cs to produce low-level radioactive sources. These sources were surrounded with cement mixed with different materials like microsilica and barite. The leaching rate of 134 Cs from the solidified radioactive source in Portland cement alone was found to be 4.481 x 10 -4 g/cm 2 per day. Mixing this Portland cement with microsilica and with barite reduced significantly the leaching rate to 1.091 x 10 -4 g/cm 2 per day and 3.153 x 10 -4 g/cm 2 per day for 1 wt.% mixing, and to 1.401 x 10 -5 g/cm 2 per day and 1.703 x 10 -4 g/cm 2 per day for 3 wt.% mixing, respectively. It was also found that the application of a latex paint reduced these leaching rates by about 6.5%, 20.3% and 13.3% for Portland cement, cement mixed with microsilica and with barite, respectively. The leaching data were also analyzed using the polynomial method. The obtained results showed that cement mixed with microsilica and with barite can be effectively used for radioactive sources solidification.

  15. Convection and macrosegregation in Al-19Cu alloy directionally solidified through an abrupt contraction in cross-section: A comparison with Al-7Si

    Science.gov (United States)

    Ghods, M.; Lauer, M.; Grugel, R. N.; Tewari, S. N.; Poirier, D. R.

    2017-02-01

    Hypoeutectic Al-19 wt. % Cu alloys were directionally solidified in cylindrical molds that featured an abrupt cross-section decrease 9.5 to 3.2 mm in diameter). Thermo-solutal convection and cross-section-change-induced shrinkage flow effects on macrosegregation were investigated. Dendrite clustering and extensive radial macrosegregation was seen, particularly in the larger cross-section before contraction. This alloy shows positive longitudinal macrosegregation near the contraction followed by negative macrosegregation right after it; the extent of macrosegregation, however, decreases with increasing growth speed. The degree of thermo-solutal convection was compared to another study investigating directional solidification of Al-7 wt. % Si [1] in order to study the effect of solutal expansion coefficient on macrosegregation. An interesting change of the radial macrosegregation profile, attributable to the area-change-induced-shrinkage flow, was observed very close to the contraction. A two-dimensional model accounting for both shrinkage and thermo-solutal convection was used to simulate solidification, the resulting steepling as well as axial and radial macrosegregation. The experimentally observed macrosegregation associated with the contraction during directional solidification was well predicted by the numerical simulations.

  16. Characterization of solidified radioactive waste and container due to the incorporation of high density polyethylene granules and powder in mortar matrices

    International Nuclear Information System (INIS)

    Peric, A.D.

    1999-01-01

    Powder and granules of the high density polyethylene (PEHD) were used to prepare mortar based matrices for immobilization of radioactive waste materials containing 137 Cs, as well as containers for solidified radioactive waste form. Seven types of matrices, differ due to the percentage of granules and filler material added, were investigated. PEHD powder and granules were added to mortar matrix preparations with the objective of improving physico-chemical characteristics of the radwaste-mortar matrix mixtures, in particular the leach-rate of the immobilized radionuclide, as well as mechanical characteristics either of mortar matrix and container. In this paper, only mechanical strength aspect of the investigated mortar and concrete container formulations, is presented. The equivalent diameter of the PEHD granules used was 2.0 mm. PEHD granules were used to replace 100 volume percent of stone granules, sifted size of 2.0 mm, normally used in the matrix preparation, in order to decrease the porosity and density of the mortar matrix and to avoid segregation of the stone particles at the bottom of the immobilized radioactive waste cylindrical form. PEHD powder, particle size of 250 micrometer, was added as filler to the mortar formulation, replacing 5, 8 and 10 wt% of the total cement weight in matrix formulation and 15 and 18 wt% of the total cement weight in container formulation. Cured samples were investigated on mechanical strength, using 150 MPa hydraulic press, in order to determine influence of added polyethylene granules and powder on samples resistance to mechanical forces that solidified waste materials and concrete containers may experience at the disposal site. Results of performed investigations have shown that samples prepared with polyethylene granules, replacing 100 wt% of the stone granules, have almost twice as much mechanical strength than samples prepared with stone aggregate. Samples prepared with PEHD granules and powder have mechanical strength

  17. Technicolor dynamics corrections to Wt-barb coupling

    International Nuclear Information System (INIS)

    Yue Chongxing; Huang Jinshu; Lu Gongru; Yang Zhengtao

    1998-01-01

    The authors consider the contributions of new gauge bosons to Wt-barb coupling in one generation technicolor (OGTC) model and topcolor assisted multiscale technicolor (TOPCMTC) model. The authors find that the exchange of diagonal extended technicolor (ETC) gauge boson has no contribution to Wt-barb coupling. Using the LEP value of R b , the authors calculate the corrections to the CKM matrix element V tb which arise from the sideways ETC gauge boson in OGTC model and the sideways ETC gauge bosons and color exchange in TOPCMTC model. The authors find that the δV tb is significantly large for a certain set of the parameters of either OGTC model or TOPCMTC model which might be detected in the Fermilab Tevatron Run 3 experiments

  18. Physical properties of monolithic U8 wt.%-Mo

    Science.gov (United States)

    Hengstler, R. M.; Beck, L.; Breitkreutz, H.; Jarousse, C.; Jungwirth, R.; Petry, W.; Schmid, W.; Schneider, J.; Wieschalla, N.

    2010-07-01

    As a possible high density fuel for research reactors, monolithic U8 wt.%-Mo ("U8Mo") was examined with regard to its structural, thermal and electric properties. X-ray diffraction by the Bragg-Brentano method was used to reveal the tetragonal lattice structure of rolled U8Mo. The specific heat capacity of cast U8Mo was determined by differential scanning calorimetry, its thermal diffusivity was measured by the laser flash method and its mass density by Archimedes' principle. From these results, the thermal conductivity of U8Mo in the temperature range from 40 °C to 250 °C was calculated; in the measured temperature range, it is in good accordance with literature data for UMo with 8 and 9 wt.% Mo, is higher than for 10 wt.% Mo and lower than for 5 wt.% Mo. The electric conductivity of rolled and cast U8Mo was measured by a four-wire method and the electron based part of the thermal conductivity calculated by the Wiedemann-Frantz law. Rolled and cast U8Mo was irradiated at about 150 °C with 80 MeV 127I ions to receive the same iodine ion density in the damage peak region as the fission product density in the fuel of a typical high flux reactor after the targeted nuclear burn-up. XRD analysis of irradiated U8Mo showed a change of the lattice parameters as well as the creation of UO 2 in the superficial sample regions; however, a phase change by irradiation was not observed. The determination of the electron based part of the thermal conductivity of the irradiated samples failed due to high measurement errors which are caused by the low thickness of the damage region in the ion irradiated samples.

  19. Radiochemical analysis of homogeneously solidified low level radioactive waste from nuclear power plants

    International Nuclear Information System (INIS)

    Sato, Kaneaki; Ikeuchi, Yoshihiro; Higuchi, Hideo

    1995-01-01

    As mentioned above, we have reliable radioanalytical methods for all kinds of homogeneously solidified wastes. We are now under studying an analytical method for pellets which are made from evaporator concentrates or resin. And we are going to study to establish new analytical method for the rad-waste including metal, cloths and so on in near future. (J.P.N.)

  20. Evaluation of Carbonation Effects on Cement-Solidified Contaminated Soil Used in Road Subgrade

    Directory of Open Access Journals (Sweden)

    Yundong Zhou

    2018-01-01

    Full Text Available Cement solidification/stabilization is widely used towards contaminated soil since it has a low price and significant improvement for the structural capacity of soil. To increase the usage of the solidified matrix, cement-solidified contaminated soil was used as road subgrade material. In this study, carbonation effect that reflected the durability on strength characteristics of cement-solidified contaminated soil and the settlement of pavement were evaluated through experimental and numerical analysis, respectively. According to results, compressive strengths of specimens with 1% Pb(II under carbonation and standard curing range from 0.44 MPa to 1.17 MPa and 0.14 MPa to 2.67 MPa, respectively. The relatively low strengths were attributed to immobilization of heavy metal, which consumed part of SiO2, Al2O3, and CaO components in the cement or kaolin and reduced the hydration and pozzolanic reaction materials. This phenomenon further decreased the strength of solidified soils. The carbonation depth of 1% Cu(II or Zn(II contaminated soils was 18 mm, which significantly increased with the increase of curing time and contamination concentration. Furthermore, the finite element calculation results showed that surface settlements decreased with the increase of modulus of subgrade and the distance away from the center. At the center, the pavement settlement was proportional to the level of traffic load.

  1. Elution behavior of heavy metals from cement solidified products of incinerated ash waste - 59102

    International Nuclear Information System (INIS)

    Meguro, Yoshihiro; Kawato, Yoshimi; Nakayama, Takuya; Tomioka, Osamu; Mitsuda, Motoyuki

    2012-01-01

    A method, in which incinerated ash is solidified with a cement material, has been developed to dispose radioactive incinerated ash waste. In order to bury the solidified product, it is required that elution of hazardous heavy metals included in the ash from the solidified products is inhibited. In this study, the elution behavior of the heavy metals from the synthetic solidified products, which included Pb(II), Cd(II), and Cr(VI) and were prepared using ordinary portland cement (OPC), blast furnace slag cement (BFS), or a cement material that showed low alkalinity (LA-Cement), was investigated. Several chemicals and materials were added as additive agents to prevent the elution of the heavy metals. When OPC was used, Cd elution was inhibited, but Pb and Cr were not enough even using the additive agent examined. FeSO 4 and Na 2 S additive agents worked effective to inhibit elution of Cr. When BFS was used, the elution of Pb, Cd and Cr was inhibited for the all products prepared. In the case of LA-Cement, the elution of Pb and Cd was inhibited for the all products, but only the product that was added FeSO 4 showed good result of the elution of Cr. (authors)

  2. IAEA coordinated research program on the evaluation of solidified high-level radioactive waste products

    International Nuclear Information System (INIS)

    Grover, J.R.; Schneider, K.J.

    1979-01-01

    A coordinated research program on the evaluation of solidified high-level radioactive waste products has been active with the IAEA since 1976. The program's objectives are to integrate research and to provide a data bank on an international basis in this subject area. Results and considerations to date are presented

  3. Effect of drying-wetting cycles on leaching behavior of cement solidified lead-contaminated soil.

    Science.gov (United States)

    Li, Jiang-Shan; Xue, Qiang; Wang, Ping; Li, Zhen-Ze; Liu, Lei

    2014-12-01

    Lead contaminated soil was treated by different concentration of ordinary Portland cement (OPC). Solidified cylindrical samples were dried at 40°C in oven for 48 h subsequent to 24h of immersing in different solution for one drying-wetting. 10 cycles were conducted on specimens. The changes in mass loss of specimens, as well as leaching concentration and pH of filtered leachates were studied after each cycle. Results indicated that drying-wetting cycles could accelerate the leaching and deterioration of solidified specimens. The cumulative leached lead with acetic acid (pH=2.88) in this study was 109, 83 and 71 mg respectively for solidified specimens of cement-to-dry soil (C/Sd) ratios 0.2, 0.3 and 0.4, compared to 37, 30, and 25mg for a semi-dynamic leaching test. With the increase of cycle times, the cumulative mass loss of specimens increased linearly, but pH of filtered leachates decreased. The leachability and deterioration of solidified specimens increased with acidity of solution. Increases of C/Sd clearly reduced the leachability and deterioration behavior. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. Influence of Short-time Oxidation on Corrosion Properties of Directionally Solidified Superalloys with Different Orientations

    Directory of Open Access Journals (Sweden)

    MA Luo-ning

    2016-07-01

    Full Text Available In order to investigate the corrosion performance on intersecting and longitudinal surfaces of unoxidized and oxidized directionally solidified superalloys, Ni-base directionally solidified superalloy DZ125 and Co-base directionally solidified superalloy DZ40M were selected. Oxidation behavior on both alloys with different orientations was investigated at 1050℃ at different times, simulating the oxidation process of vanes or blades in service; subsequent electrochemical performance in 3.5%NaCl aqueous solution was studied on two orientations of unoxidized and oxidized alloys, simulating the corrosion process of superalloy during downtime. The results show that grain boundaries and sub-boundaries of directionally solidified superalloys are susceptible to corrosion and thus longitudinal surface with lower area fraction of grain boundaries has higher corrosion resistance. Compared to intersecting surface of alloys, the structure of grain boundaries of longitudinal surface is less conducive to diffusion and thus the oxidation rate on longitudinal surface is lower. Formation of oxide layers on alloys after short-time oxidation provides protective effect and enhances the corrosion resistance.

  5. Performance criteria for solidified high-level radioactive wastes. Environmental impact statement. Revision 1

    International Nuclear Information System (INIS)

    1977-09-01

    This draft Environmental Impact Statement on performance criteria for solidified high-level radioactive wastes (PCSHLW) covers: considerations for PCSHLW development, the proposed rulemaking, characteristics of the PCSHLW, environmental impacts of the proposed PCSHLW, alternatives to the PCSHLW criteria, and cost/benefit/risk evaluation. Five appendices are included to support the technical data required in the Environmental Impact Statement

  6. The evaluation of solidifying performance of heavy metal waste using cementitious materials (2)

    International Nuclear Information System (INIS)

    Fujita, Hideki; Harasawa, Shuichi

    2005-02-01

    Some of radioactive waste generated from JNC's facilities contain the poisonous substances such as lead, cadmium and mercury. In order to establish an appropriate method of the treatment of these heavy metals, solidification performance was evaluated using cementitious materials. In this report, the solidification performance of lead and mercury, which accounts for relatively high ratio in total wastes, was evaluated. The results are summarized below: 1. The test of stabilization process of mercury. The conversion process from mercury to the powdery mercury sulfide (red) was examined on the beaker scale. As a result, it was confirmed that the conversion was possible using the liquid phase reaction at 80deg C by the addition of sulfur powder with the NaOH solution. After the process, the mercury concentration in the filtrate was relatively high (0.6 mass%), so it was judged that the reuse of the recovered mercury waste fluid was indispensable. 2. The fabrication and evaluation of solidified wastes. The solidified waste were fabricated with cementitious material, and were evaluated by the measurement of one-axis compressive strength, the elution ratio of lead, mercury and so on. Powdery lead sulfide and the mercury sulfide of reagent were used as model waste. (1) solidification test of the lead waste. It was confirmed one-axis compressive strength for all solidified waste to pass the technical standards 15 kg/cm 2 (1.5 Mpa) for homogeneously solidified waste as the Low-level Radioactive Waste Disposal Center in Aomori Prefecture, and as for the elution ratio of lead, it had obtained the better result (0.06 mg/L) at the case of solidification of sulfide lead 30 mass% packed in the total solidified waste by using Highly Fly-ash contained Silica fume Cement (HFSC) than standard value (0.3 mg/L) at Regulations of Waste Management and Public Cleansing Law. Additionally, it was confirmed the using admixture of the inorganic reducing agent such as the Iron (II) chloride

  7. Multiscale modeling of a low magnetostrictive Fe-27wt%Co-0.5wt%Cr alloy

    Science.gov (United States)

    Savary, M.; Hubert, O.; Helbert, A. L.; Baudin, T.; Batonnet, R.; Waeckerlé, T.

    2018-05-01

    The present paper deals with the improvement of a multi-scale approach describing the magneto-mechanical coupling of Fe-27wt%Co-0.5wt%Cr alloy. The magnetostriction behavior is demonstrated as very different (low magnetostriction vs. high magnetostriction) when this material is submitted to two different final annealing conditions after cold rolling. The numerical data obtained from a multi-scale approach are in accordance with experimental data corresponding to the high magnetostriction level material. A bi-domain structure hypothesis is employed to explain the low magnetostriction behavior, in accordance with the effect of an applied tensile stress. A modification of the multiscale approach is proposed to match this result.

  8. Improvement in mechanical properties of hypereutectic Al-Si-Cu alloys through sono-solidified

    Directory of Open Access Journals (Sweden)

    Yoshiki Tsunekawa

    2014-07-01

    Full Text Available For the wider applications, it is necessary to improve the ductility as well as the strength and wear-resistance of hypereutectic Al-Si-Cu alloys, which are typical light-weight wear-resistant materials. An increase in the amounts of primary silicon particles causes the modified wear-resistance of hypereutectic Al-Si-Cu alloys, but leads to the poor strength and ductility. It is known that dual phase steels composed of hetero-structure have succeeded in bringing contradictory mechanical properties of high strength and ductility concurrently. In order to apply the idea of hetero-structure to hypereutectic Al-Si-Cu alloys for the achievement of high strength and ductility along with wear resistance, ultrasonic irradiation of the molten metal during the solidification, which is called sono-solidification, was carried out from its molten state to just above the eutectic temperature. The sono-solidified Al-17Si-4Cu alloy is composed of hetero-structure, which are, hard primary silicon particles, soft non-equilibrium a -Al phase and the eutectic region. Rheo-casting was performed at just above the eutectic temperature with sono-solidified slurry to shape a disk specimen. After the rheo-casting with modified sonosolidified slurry held for 45 s at 570 篊, the quantitative optical microscope observation exhibits that the microstructure is composed of 18area% of hard primary silicon particles and 57area% of soft a -Al phase. In contrast, there exist only 5 area% of primary silicon particles and no a -Al phase in rheo-cast specimen with normally solidified slurry. Hence the tensile tests of T6 treated rheo-cast specimens with modified sono-solidified slurry exhibit improved strength and 5% of elongation, regardless of having more than 3 times higher amounts of primary silicon particles compared to that of rheo-cast specimen with normally solidified slurry.

  9. Top Polarisation in H-t and Wt production

    International Nuclear Information System (INIS)

    Godbole, R.M.; Hartgring, L.; Niessen, I.; White, C.D.

    2012-01-01

    We consider laboratory frame observables (like the azimuthal angle between the top quark and its decay lepton or the polar angle between the top quark and leptonic directions) obtained from leptonic decay products of top quarks produced in association with a charged Higgs or W boson. These are robust against QCD corrections to top quark decay, and can be used to pin down the parameter space of a charged Higgs boson, or reduce backgrounds in H - t and (Standard Model) Wt production. Polarisation information can efficiently be used to distinguish single top quark production processes from their backgrounds, as well as to pin down the parameters of a charged Higgs boson model

  10. Microstructure evolution in undercooled Al–8 wt%Fe melts: Comparison between terrestrial and parabolic flight conditions

    International Nuclear Information System (INIS)

    Chen, J.; Lengsdorf, R.; Henein, H.; Herlach, D.M.; Dahlborg, U.; Calvo-Dahlborg, M.

    2013-01-01

    Highlights: ► A comparison between the solidification using electromagnetic levitation of Al–8 wt%Fe under terrestrial and reduced gravity conditions is shown. ► The microstructure evolution during solidification of Al–8 wt%Fe is formulated with the aid of a comprehensive set of complementary characterization techniques. ► Identification of Al–Fe intermetallics using TEM and Rietveld analysis. -- Abstract: Al–8 wt%Fe, a hypereutectic alloy, was studied under electromagnetic levitation (EML) solidification conditions in both terrestrial and reduced gravity conditions. The latter was carried out on the A300 aircraft using the TEMPUS facility. The solidified samples were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction and neutron diffraction techniques. The results are interpreted in the light of the temperature–time measurements taken in situ during the solidification process in the EML. It is shown that both samples experienced some undercooling for the solidification of the primary Al–Fe intermetallic phase, which is likely Al m Fe. The solidification path continues with the nucleation and growth of Al 13 Fe 4 followed by primary α-Al. These last two phases do not seem to show any measureable undercooling and recalescence events. Finally, the metastable Al x Fe (where x = 5) nucleates starting with the formation of eutectic. This metastable intermetallic continues the eutectic growth as Al 13 Fe 4 . The morphology differences of the intermetallics growing under terrestrial and reduced gravity conditions are clear with acicular morphology for the former and a star like morphology for the latter. The primary α-Al has a clear strong textured structure in the reduced gravity sample, while a weak one is observed in the terrestrially processed sample. The difference in texture is attributed to the weaker fluid flow occurring in the droplet under reduced gravity conditions while the difference in

  11. The evaluation of solidifying performance of heavy metal waste using cementitious materials

    International Nuclear Information System (INIS)

    Takei, Akihiko; Fujita, Hideki; Harasawa, Shuichi

    2004-02-01

    Some of radioactive waste generated form JNC's facilities contain the poisonous substances such as lead, cadmium and mercury. In order to establish an appropriate method of the treatment of these heavy metals, solidification performance was evaluated using cementitious materials. In this report, the solidification performance of lead, which accounts for relatively high ratio in total wastes, was evaluated. The results are summarized below: 1. The test of stabilization process of lead: The conversion process from block lead to the powdery lead sulfide was examined on the beaker scale. As a result, it was confirmed that the conversion was possible using the liquid phase reaction by the addition of thiourea after block lead had been dissolved by the acetic acid with bubbling air. After the process, the lead concentration in the filtrate was extremely low (0.02 mg/L), so it was judged that almost all of the lead was converted and recovered as lead sulfide. 2. The fabrication and evaluation of solidified wastes: Five types of solidified waste were fabricated with different binder, and were evaluated by the measurement of one-axis compressive strength, porosity, the elution ratio of lead, and so on. Powdery lead and sulfide lead reagent were used as model waste. As a result of the test, it was confirmed one-axis compressive strength for all solidified waste to pass the technical standards 15 kg/cm 2 (1.5 MPa) for homogeneously solidified waste as the Low-level Radioactive Waste Disposal Center in Aomori Prefecture, and as for the elution ratio of lead, it had obtained the better result (0.27 mg/L) at the case of solidification of sulfide lead 20 mass% packed in the total solidified waste by using low alkaline cement (including Hauyne mineral) than standard value (0.3 mg/L) at Regulations of Waste Management and Public Cleansing Law. Moreover, it was understood that the elution of lead had high relationship with not only the character of the binder but also the physical

  12. Optimization of Surrounding Reflector Material for Hyb-WT

    International Nuclear Information System (INIS)

    Tariq Siddique, M.; Hong, Song Hee; Kim, Myung Hyun

    2013-01-01

    The choice of reflector material is crucial for fusion and hybrid reactors as it was for the fission reactors. Multiple reflector materials were studied for pure fusion blanket design. The purpose of reflector in fusion blanket is to enhance the tritium breeding ratio (TBR). In fusion fission hybrid blanket the roll of reflector is slightly changed as it include the fission core and the performance of fission core also needs to be optimized and evaluated with the choice of reflector material, along with the enhancement of TBR. The performance parameters of Hyb-WT are significantly influenced by the choice of reflector material. TiC is best for TRU transmutation, TBR and reduced the neutron wall loading and graphite is best for FP transmutation. Strategy of multi reflector materials gives the best TRU and FP transmutation performance and also enhanced TBR with reduced neutron wall loading and it is a better choice for Hyb-WT reflector. The neutron flux is primarily dominated by the fission neutrons

  13. Phase Transformation Behavior of Medium Manganese Steels with 3 Wt Pct Aluminum and 3 Wt Pct Silicon During Intercritical Annealing

    Science.gov (United States)

    Sun, Binhan; Fazeli, Fateh; Scott, Colin; Yue, Stephen

    2016-10-01

    Medium manganese steels alloyed with sufficient aluminum and silicon amounts contain high fractions of retained austenite adjustable to various transformation-induced plasticity/twinning-induced plasticity effects, in addition to a reduced density suitable for lightweight vehicle body-in-white assemblies. Two hot rolled medium manganese steels containing 3 wt pct aluminum and 3 wt pct silicon were subjected to different annealing treatments in the present study. The evolution of the microstructure in terms of austenite transformation upon reheating and the subsequent austenite decomposition during quenching was investigated. Manganese content of the steels prevailed the microstructural response. The microstructure of the leaner alloy with 7 wt pct Mn (7Mn) was substantially influenced by the annealing temperature, including the variation of phase constituents, the morphology and composition of intercritical austenite, the Ms temperature and the retained austenite fraction. In contrast, the richer variant 10 wt pct Mn steel (10Mn) exhibited a substantially stable ferrite-austenite duplex phase microstructure containing a fixed amount of retained austenite which was found to be independent of the variations of intercritical annealing temperature. Austenite formation from hot band ferrite-pearlite/bainite mixtures was very rapid during annealing at 1273 K (1000 °C), regardless of Mn contents. Austenite growth was believed to be controlled at early stages by carbon diffusion following pearlite/bainite dissolution. The redistribution of Mn in ferrite and particularly in austenite at later stages was too subtle to result in a measureable change in austenite fraction. Further, the hot band microstructure of both steels contained a large fraction of coarse-grained δ-ferrite, which remained almost unchanged during intercritical annealing. A recently developed thermodynamic database was evaluated using the experimental data. The new database achieved a better agreement

  14. Validation of the solidifying soil process using laser-induced breakdown spectroscopy

    Science.gov (United States)

    Lin, Zhao-Xiang; Liu, Lin-Mei; Liu, Lu-Wen

    2016-09-01

    Although an Ionic Soil Stabilizer (ISS) has been widely used in landslide control, it is desirable to effectively monitor the stabilization process. With the application of laser-induced breakdown spectroscopy (LIBS), the ion contents of K, Ca, Na, Mg, Al, and Si in the permeable fluid are detected after the solidified soil samples have been permeated. The processes of the Ca ion exchange are analyzed at pressures of 2 and 3 atm, and it was determined that the cation exchanged faster as the pressure increased. The Ca ion exchanges were monitored for different stabilizer mixtures, and it was found that a ratio of 1:200 of ISS to soil is most effective. The investigated plasticity and liquidity indexes also showed that the 1:200 ratio delivers the best performance. The research work indicates that it is possible to evaluate the engineering performances of soil solidified by ISS in real time and online by LIBS.

  15. Accelerated leach testing of radionuclides from solidified low-level waste

    International Nuclear Information System (INIS)

    Pietrzak, R.F.; Fuhrmann, M.; Franz, E.M.; Heiser, J. III; Colombo, P.

    1989-01-01

    This paper describes some of the work performed to develop an accelerated leach test designed to provide data that show long-term leaching behavior of solidified waste in a relatively short period of testing (1,2). The need for an accelerated leach test stems from the fact that the response of an effectively solidified waste form to the leaching process is so slow that a very long time is required to complete a test which shows the long-term leaching behavior of a waste form. Because of time limitations, as well as economic considerations, most studies have been limited to the early stages of the leaching process which is predominantly controlled by diffusion, although acknowledged to be due to also dissolution, corrosion or ion-exchange

  16. Modeling Macrosegregation in Directionally Solidified Aluminum Alloys under Gravitational and Microgravitational Conditions.

    Energy Technology Data Exchange (ETDEWEB)

    Lauer, Mark A.; Poirier, David R.; Erdmann, Robert G.; Tewari, Surendra N.; Madison, Jonathan D

    2014-09-01

    This report covers the modeling of seven directionally solidified samples, five under normal gravitational conditions and two in microgravity. A model is presented to predict macrosegregation during the melting phases of samples solidified under microgravitational conditions. The results of this model are compared against two samples processed in microgravity and good agreement is found. A second model is presented that captures thermosolutal convection during directional solidification. Results for this model are compared across several experiments and quantitative comparisons are made between the model and the experimentally obtained radial macrosegregation profiles with good agreement being found. Changes in cross section were present in some samples and micrographs of these are qualitatively compared with the results of the simulations. It is found that macrosegregation patterns can be affected by changing the mold material.

  17. Functions and requirements document for interim store solidified high-level and transuranic waste

    Energy Technology Data Exchange (ETDEWEB)

    Smith-Fewell, M.A., Westinghouse Hanford

    1996-05-17

    The functions, requirements, interfaces, and architectures contained within the Functions and Requirements (F{ampersand}R) Document are based on the information currently contained within the TWRS Functions and Requirements database. The database also documents the set of technically defensible functions and requirements associated with the solidified waste interim storage mission.The F{ampersand}R Document provides a snapshot in time of the technical baseline for the project. The F{ampersand}R document is the product of functional analysis, requirements allocation and architectural structure definition. The technical baseline described in this document is traceable to the TWRS function 4.2.4.1, Interim Store Solidified Waste, and its related requirements, architecture, and interfaces.

  18. Microstructure of directionally solidified Ti-Fe eutectic alloy with low interstitial and high mechanical strength

    Science.gov (United States)

    Contieri, R. J.; Lopes, E. S. N.; Taquire de La Cruz, M.; Costa, A. M.; Afonso, C. R. M.; Caram, R.

    2011-10-01

    The performance of Ti alloys can be considerably enhanced by combining Ti and other elements, causing an eutectic transformation and thereby producing composites in situ from the liquid phase. This paper reports on the processing and characterization of a directionally solidified Ti-Fe eutectic alloy. Directional solidification at different growth rates was carried out in a setup that employs a water-cooled copper crucible combined with a voltaic electric arc moving through the sample. The results obtained show that a regular fiber-like eutectic structure was produced and the interphase spacing was found to be a function of the growth rate. Mechanical properties were measured using compression, microindentation and nanoindentation tests to determine the Vickers hardness, compressive strength and elastic modulus. Directionally solidified eutectic samples presented high values of compressive strength in the range of 1844-3000 MPa and ductility between 21.6 and 25.2%.

  19. Research on the compressive strength of basic magnesium salts and cyanide slag solidified body

    Science.gov (United States)

    Tu, Yubo; Han, Peiwei; Ye, Shufeng; Wei, Lianqi; Zhang, Xiaomeng; Fu, Guoyan; Yu, Bo

    2018-02-01

    The solidification of cyanide slag by using basic magnesium salts could reduce pollution and protect the environment. Experiments were carried out to investigate the effects of age, mixing amount of cyanide slag, water cement ratio and molar ratio of MgO to MgSO4 on the compressive strength of basic magnesium salts and cyanide slag solidified body in the present paper. It was found that compressive strength of solidified body increased with the increase of age, and decreased with the increase of mixing amount of cyanide slag and water cement ratio. The molar ratio of MgO to MgSO4 should be controlled in the range from 9 to 11 when the mixing amount of cyanide slag was larger than 80 mass%.

  20. Room Temperature Mechanical Properties of A356 Alloy with Ni Additions from 0.5 Wt to 2 Wt %

    Directory of Open Access Journals (Sweden)

    Lucia Lattanzi

    2018-03-01

    Full Text Available In recent years, the influence of Ni on high-temperature mechanical properties of casting Al alloys has been extensively examined in the literature. In the present study, room temperature mechanical properties of an A356 alloy with Ni additions from 0.5 to 2 wt % were investigated. The role of Ni-based compounds and eutectic Si particles in reinforcing the Al matrix was studied with image analysis and was then related to tensile properties and microhardness. In the as-cast condition, the formation of the 3D network is not sufficient to determine an increase of mechanical properties of the alloys since fracture propagates by cleavage through eutectic Si particles and Ni aluminides or by the debonding of brittle phases from the aluminum matrix. After T6 heat treatment the increasing amount of Ni aluminides, due to further addition of Ni to the alloy, together with their brittle behavior, leads to a decrease of yield strength, ultimate tensile strength, and Vickers microhardness. Despite the fact that Ni addition up to 2 wt % hinders spheroidization of eutectic Si particles during T6 heat treatment, it also promotes the formation of a higher number of brittle Ni-based compounds that easily promote fracture propagation.

  1. Comparative analysis of mechanical characteristics of solidified concentrates from BWR system using Yugoslav and Italian cements

    International Nuclear Information System (INIS)

    Plecas, I.; Peric, A.; Drljaca, J.; Kostadinovic, A.

    1987-01-01

    In this paper, properties of Italian and Yugoslav cement mixture with BWR evaporation concentrates were compared, research was held upon fifteen samples, according to the adequate formulations. Samples were made in standard cube form, side 10 cm. Functional relationship between decreasing the compressive strength and amount of incorporated BWR concentrate cement mixture was developed. The results of research showed nearly the same mechanical properties of solidified BWR concentrate with Italian and Yugoslav cements. (author)

  2. Leach testing of simulated ion-exchange resin waste solidified in cement

    International Nuclear Information System (INIS)

    Muurinen, A.K.; Uotila, P.I.; Ovaskainen, R.M.

    Leach tests were carried out on ion-exchange resins solidified in cement. Three product mixtures, two isotopes and four leachants at two temperatures, were tested. The increase of resin content increased the leaching of Cs-137; the effect of silix admixture was negligible. The type of the leachant has a stronger influence on Co-60 than on Cs-137. The increase of temperature usually also increased leaching. (author)

  3. The use of Nb in rapid solidified Al alloys and composites

    Energy Technology Data Exchange (ETDEWEB)

    Audebert, F., E-mail: metal@fi.uba.ar [Advanced Materials Group, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, Ciudad de Buenos Aires 1063 (Argentina); Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Department of Mechanical Engineering and Mathematical Sciences, Oxford Brookes University, Wheatley Campus, OX33 1HX Oxford (United Kingdom); Galano, M. [Department of Materials, University of Oxford, Parks Road, OX1 3PH Oxford (United Kingdom); Saporiti, F. [Advanced Materials Group, Facultad de Ingeniería, Universidad de Buenos Aires, Paseo Colón 850, Ciudad de Buenos Aires 1063 (Argentina)

    2014-12-05

    Highlights: • The use of Nb in RS Al alloys and composites has been reviewed. • Nb was found to improve the GFA of rapid solidified Al–Fe and Al–Ni alloys. • Nb has higher effect in increasing the corrosion resistance than RE in Al–Fe alloys. • Nb improves the stability of the Al–Fe–Cr icosahedral phase. • Nb improves strength, ductility and toughness of nanoquasicrystalline Al matrix composites. - Abstract: The worldwide requirements for reducing the energy consumption and pollution have increased the demand of new and high performance lightweight materials. The development of nanostructured Al-based alloys and composites is a key direction towards solving this demand. High energy prices and decreased availability of some alloying elements open up the opportunity to use non-conventional elements in Al alloys and composites. In this work the application of Nb in rapid solidified Al-based alloys and Al alloys matrix composites is reviewed. New results that clarify the effect of Nb on rapid solidified Al alloys and composites are also presented. It is observed that Nb stabilises the icosahedral Al–Fe/Cr clusters, enhances the glass forming ability and shifts the icosahedral phase decomposition towards higher temperatures. Nb provides higher corrosion resistance with respect to the pure Al and Al–Fe–RE (RE: rare earth) alloys in the amorphous and crystalline states. The use of Nb as a reinforcement to produce new Al alloy matrix composites is explored. It is observed that Nb provides higher strength, ductility and toughness to the nanoquasicrystalline matrix composite. Nb appears as a new key element that can improve several properties in rapid solidified Al alloys and composites.

  4. Structure and transformation behaviour of a rapidly solidified Al-Y-Ni-Co-Pd alloy

    International Nuclear Information System (INIS)

    Louzguine-Luzgin, D.V.; Inoue, A.

    2005-01-01

    An as-solidified structure and transformation behaviour on heating of the rapidly solidified Al-Y-Ni-Co-Pd alloy was studied by X-ray diffractometry (XRD), transmission electron microscopy (TEM), differential scanning and isothermal calorimetries. The Al-Y-Ni-Co-Pd ribbon samples have been produced by the melt spinning technique and heat treated using a differential scanning calorimeter (DSC). The addition of Pd to Al-Y-Ni-Co alloys caused disappearance of the supercooled liquid region as well as the formation of the highly dispersed primary α-Al nanoparticles about 3-7 nm in size homogeneously embedded in the glassy matrix upon solidification. An extremely high density of precipitates of the order of 10 24 m -3 is obtained. These particles start growing at the temperature below a glass-transition temperature. The results presented in this paper indicate that some of so-called 'marginal' glass-formers in as-solidified state are actually not glassy alloys with pre-existed nuclei but crystal-glassy nanocomposites

  5. Effect of tensile mean stress on fatigue behavior of single-crystal and directionally solidified superalloys

    Science.gov (United States)

    Kalluri, Sreeramesh; Mcgaw, Michael A.

    1990-01-01

    Two nickel base superalloys, single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf, were studied in view of the potential usage of the former and usage of the latter as blade materials for the turbomachinery of the space shuttle main engine. The baseline zero mean stress (ZMS) fatigue life (FL) behavior of these superalloys was established, and then the effect of tensile mean stress (TMS) on their FL behavior was characterized. At room temperature these superalloys have lower ductilities and higher strengths than most polycrystalline engineering alloys. The cycle stress-strain response was thus nominally elastic in most of the fatigue tests. Therefore, a stress range based FL prediction approach was used to characterize both the ZMS and TMS fatigue data. In the past, several researchers have developed methods to account for the detrimental effect of tensile mean stress on the FL for polycrystalline engineering alloys. However, the applicability of these methods to single crystal and directionally solidified superalloys has not been established. In this study, these methods were applied to characterize the TMS fatigue data of single crystal PWA 1480 and directionally solidified MAR-M 246 + Hf and were found to be unsatisfactory. Therefore, a method of accounting for the TMS effect on FL, that is based on a technique proposed by Heidmann and Manson was developed to characterize the TMS fatigue data of these superalloys. Details of this method and its relationship to the conventionally used mean stress methods in FL prediction are discussed.

  6. U-8 wt %Mo and 7 wt %Mo alloys powder obtained by an hydride-de hydride process

    International Nuclear Information System (INIS)

    Balart, Silvia N.; Bruzzoni, Pablo; Granovsky, Marta S.; Gribaudo, Luis M. J.; Hermida, Jorge D.; Ovejero, Jose; Rubiolo, Gerardo H.; Vicente, Eduardo E.

    2000-01-01

    Uranium-molybdenum alloys are been tested as a component in high-density LEU dispersion fuels with very good performances. These alloys need to be transformed to powder due to the manufacturing requirements of the fuels. One method to convert ductile alloys into powder is the hydride-de hydride process, which takes advantage of the ability of the U-α phase to transform to UH 3 : a brittle and relatively low-density compound. U-Mo alloys around 7 and 8 wt % Mo were melted and heat treated at different temperature ranges in order to partially convert γ -phase to α -phase. Subsequent hydriding transforms this α -phase to UH 3 . The volume change associated to the hydride formation embrittled the material which ends up in a powdered alloy. Results of the optical metallography, scanning electron microscopy, X-ray diffraction during different steps of the process are shown. (author)

  7. Identification of Intermetallic Compounds and Its Formation Mechanism in Boron Steel Hot-Dipped in Al-7 wt.% Mn Alloy

    Directory of Open Access Journals (Sweden)

    Sung-Yun Kwak

    2017-12-01

    Full Text Available In laser welding and hot stamping Al-Si-coated boron steel, there is a problem that the strength of the joint is lowered due to ferrite formation in the fusion zone. The purpose of this study is to develop an Al-7 wt.% Mn hot-dip coating in which Mn, an austenite stabilizing element, replaces the ferrite stabilizing element Si. The nucleation and formation mechanism of the reaction layer was studied in detail by varying the dipping time between 0 and 120 s at 773 °C. The microstructure and phase constitution of the reaction layer were investigated by various observational methods. Phase formation is discussed using a phase diagram calculated by Thermo-CalcTM. Under a 30 s hot-dipping process, no reaction occurred due to the formation of a Fe3O4 layer on the steel surface. The Fe3O4 layer decomposed by a reduction reaction with Al-Mn molten alloy, constituent elements of steel dissolved into a liquid, and the reaction-layer nucleus was formed toward the liquid phase. A coated layer consists of a solidified layer of Al and Al6Mn and a reactive layer formed beneath it. The reaction layer is formed mainly by inter-diffusion of Al and Fe in the solid state, which is arranged on the steel in the order of Al11Mn4 → FeAl3 (θ → Fe2Al5 (η phases, and the Fe3AlC (κ in several nm bands formed at the interface between the η-phase and steel.

  8. Columnar and Equiaxed Solidification of Al-7 wt.% Si Alloys in Reduced Gravity in the Framework of the CETSOL Project

    Science.gov (United States)

    Zimmermann, G.; Sturz, L.; Nguyen-Thi, H.; Mangelinck-Noel, N.; Li, Y. Z.; Gandin, C.-A.; Fleurisson, R.; Guillemot, G.; McFadden, S.; Mooney, R. P.; Voorhees, P.; Roosz, A.; Ronaföldi, A.; Beckermann, C.; Karma, A.; Chen, C.-H.; Warnken, N.; Saad, A.; Grün, G.-U.; Grohn, M.; Poitrault, I.; Pehl, T.; Nagy, I.; Todt, D.; Minster, O.; Sillekens, W.

    2017-08-01

    During casting, often a dendritic microstructure is formed, resulting in a columnar or an equiaxed grain structure, or leading to a transition from columnar to equiaxed growth (CET). The detailed knowledge of the critical parameters for the CET is important because the microstructure affects materials properties. To provide unique data for testing of fundamental theories of grain and microstructure formation, solidification experiments in microgravity environment were performed within the European Space Agency Microgravity Application Promotion (ESA MAP) project Columnar-to-Equiaxed Transition in SOLidification Processing (CETSOL). Reduced gravity allows for purely diffusive solidification conditions, i.e., suppressing melt flow and sedimentation and floatation effects. On-board the International Space Station, Al-7 wt.% Si alloys with and without grain refiners were solidified in different temperature gradients and with different cooling conditions. Detailed analysis of the microstructure and the grain structure showed purely columnar growth for nonrefined alloys. The CET was detected only for refined alloys, either as a sharp CET in the case of a sudden increase in the solidification velocity or as a progressive CET in the case of a continuous decrease of the temperature gradient. The present experimental data were used for numerical modeling of the CET with three different approaches: (1) a front tracking model using an equiaxed growth model, (2) a three-dimensional (3D) cellular automaton-finite element model, and (3) a 3D dendrite needle network method. Each model allows for predicting the columnar dendrite tip undercooling and the growth rate with respect to time. Furthermore, the positions of CET and the spatial extent of the CET, being sharp or progressive, are in reasonably good quantitative agreement with experimental measurements.

  9. Effect of rare-earth elements and quenching wheel speed on the structure, mechanical and thermal properties of rapidly solidified AZ91 Mg melt-spun ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Ekrami, A. [Iran University of Industries & Mines, Faculty of Engineering & High-Technology (Iran, Islamic Republic of); Shahri, F., E-mail: fshahri@irost.ir [Iranian Research Organization for Science & Technology, Department of Advanced Materials & Renewable Energy (Iran, Islamic Republic of); Mirak, A. [Iran University of Industries & Mines, Faculty of Engineering & High-Technology (Iran, Islamic Republic of)

    2017-01-27

    In this work, an attempt is made to study the effects of rare-earth elements as an additive (2 wt% of Ce base misch-metal) and various quenching wheel speeds (10–40 m/s) on the microstructure, thermal and mechanical properties of rapidly solidified AZ91 alloy prepared by single roller melt-spinning process. In this respect, all of the samples were studied using various techniques such as x-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), differential scanning calorimetry (DSC) and mechanical properties such as microhardness and tensile tests. The finding bore witness to proposed hypothesis in this study illustrating due to high affinity between Al and RE by adding 2 wt% rare-earth elements in the AZ91alloy, thermally stable Al{sub x}RE{sub y} intermetallic compounds are precipitated and the formation of β-Mg{sub 17}Al{sub 12} phases is reduced. DSC results revealed that by adding RE to AZ91 alloy, AlRE phases got stable up to 500 °C, while for the AZ91 sample, β-Mg{sub 17}Al{sub 12} phase was formed at temperature about 180 °C and then with increasing of temperature dissolved at 410 °C in the α-Mg matrix. Further it has been observed that the higher was the quenching wheel speed, the smaller was the grain size which in turn gives rise to a higher tensile properties (from 406 MPa for quenching wheel speed of 10 m/s to 510 MPa for 40 m/s) for the MM-added alloys. Tensile strength of 386 MPa was obtained for the AZ91 pure alloy which is prepared at wheel speed of 40 m/sec.

  10. Comparative Study on the Grain Refinement of Al-Si Alloy Solidified under the Impact of Pulsed Electric Current and Travelling Magnetic Field

    Directory of Open Access Journals (Sweden)

    Yunhu Zhang

    2016-07-01

    Full Text Available It is high of commercial importance to generate the grain refinement in alloys during solidification by means of electromagnetic fields. Two typical patterns of electromagnetic fields, pulsed electric currents (ECP and traveling magnetic field (TMF, are frequently employed to produce the finer equiaxed grains in solidifying alloys. Various mechanisms were proposed to understand the grain refinement in alloys caused by ECP and TMF. In this paper, a comparative study is carried out in the same solidification regime to investigate the grain refinement of Al-7 wt. %Si alloy driven by ECP and TMF. Experimental results show that the application of ECP or TMF can cause the same grain refinement occurrence period, during which the refinement of primary Al continuously occurs. In addition, the related grain refinement mechanisms are reviewed and discussed, which shows the most likely one caused by ECP and TMF is the promoted dendrite fragmentation as the result of the ECP-induced or TMF-induced forced flow. It suggests that the same grain refinement process in alloys is provoked when ECP and TMF are applied in the same solidification regime, respectively.

  11. Thermomechanical fatigue of Sn-37 wt.% Pb model solder joints

    International Nuclear Information System (INIS)

    Liu, X.W.; Plumbridge, W.J.

    2003-01-01

    The fatigue of Sn-37 wt.% Pb model solder joints has been investigated under thermomechanical and thermal cycling. Based upon an analysis of displacements during thermomechancial cycling, a model solder joint has been designed to simulate actual joints in electronic packages. The strain-stress relationship, characterised by hysteresis loops, was determined during cycling from 30 to 125 deg. C, and the stress-range monitored throughout. The number of cycles to failure, as defined by the fall in stress range, was correlated to strain range and strain energy. The strain hardening exponent, k, varied with the definition of failure and, when a stress-range drop of 50% was used, it was 0.46. Cracks were produced during pure thermal cycling without external strains applied. These arose due to the local strains caused by thermal expansion mismatches between the solder and Cu 6 Sn 5 intermetallic layer, between the phases of solder, and due to the anisotropy of the materials. The fatigue life under thermomechanical cycling was significantly inferior to that obtained in isothermal mechanical cycling. A factor contributing to this inferiority is the internal damage produced during temperature cycling

  12. Optimization of Graphene Conductive Ink with 73 wt% Graphene Contents.

    Science.gov (United States)

    Xu, Chang-Yan; Shi, Xiao-Mei; Guo, Lu; Wang, Xi; Wang, Xin-Yi; Li, Jian-Yu

    2018-06-01

    With the pace of development accelerating in printed electronics, the fabrication and application of conductive ink have been brought into sharp focus in recent years. The discovery of graphene also unfolded a vigorous research campaign. In this paper, we prepared graphene conductive ink and explored the feasibility of applying the ink to flexible paper-based circuit. Since experimental study concentrating upon ink formulation was insufficient, orthogonal test design was used in the optimization of preparation formula of conductive ink for the first time. The purpose of this study was to determine the effect of constituent dosage on conductivity of graphene conductive ink, so as to obtain the optimized formula and prepare graphene conductive ink with good conductivity. Characterization of optimized graphene conductive ink we fabricated showed good adhesion to substrate and good resistance to acid and water. The graphene concentration of the optimized ink reached 73.17 wt% solid content. Particle size distribution of graphene conductive ink was uniform, which was about 1940 nm. Static surface tension was 28.9 mN/m and equilibrium contact angle was 23°, demonstrating that conductive ink had good wettability. Scanning Electron Microscope (SEM) analysis was also investigated, moreover, the feasibility of lightening a light-emitting diode (LED) light was verified. The graphene conductive ink with optimized formula can be stored for almost eight months, which had potential applications in flexible paper-based circuit in the future.

  13. Effect of conventional and subzero treating on the mechanical properties of aged martensitic Fe-12 wt.% Ni-X wt.% Mn alloys

    International Nuclear Information System (INIS)

    Nedjad, S. Hossein; Nili-Ahmadabadi, M.; Mahmudi, R.; Farhangi, H.

    2003-01-01

    Fe-Ni-Mn maraging alloys are suffering from sever embrittlement after aging. Mechanism of the embrittelement has not been well understood yet. Segregation of Mn atoms or formation of Austenite particles at prior Austenite grain boundaries (PAGBs) have been reported as embrittelement mechanisms while it remains controversial now. For better understanding of embrittelement behavior, effect of subzero treating after aging, double aging and modification of alloy composition on the mechanical properties and fracture behavior were investigated. Alloys of chemical compositions Fe-11.9 wt.% Ni-6.3 wt.% Mn and Fe-10.5 wt.% Ni-5.8 wt.% Mo-3 wt.% Mn were studied. Double solution annealing was performed at 1223 and 1093 K for 3.6 ks followed by water quenching. After aging at 723 K for 0.9 ks (under aging) and 172.8 ks (over aging), tensile properties of specimens heat treated conventionally and cryogenically were measured. Double aging was done at 623 K for 3.6 ks followed by a step aging at 753, 783 and 803 K. Aging behavior and tensile properties of Fe-10.5 wt.% Ni-5.8 wt.% Mo-3 wt.% Mn were investigated after aging at 773 K. Results showed that alloy modification yields reasonable tensile properties while subzero treatment and double aging couldn't improve tensile properties. An insight toward more investigation of the embrittelement mechanism was made on the basis of this study

  14. Hot deformation of U-9 wt% Mo

    International Nuclear Information System (INIS)

    Kapoor, R.; Thota, M.K.; Chakravartty, J.K.; Basak, C.B.; Jha, S.K.; Hussain, M.M.

    2016-01-01

    Uranium – 9 wt% molybdenum in the as-extruded condition was deformed in compression in vacuum at temperatures from 850 to 1000 °C and strain rates from 3 × 10"−"3 to 1 s"−"1. The strain rate sensitivity (m) was computed and plotted as iso-strain rate sensitivity contour plots. m was around 0.33 at 950–1000 °C at strain rate of 3 × 10"−"3 s"−"1. Electron backscatter diffraction showed that at 1000 °C–3 × 10"−"3 s"−"1 grains refined, fraction of high angle boundaries increased and the average local misorientation reduced, all indicative of the occurrence of dynamic recrystallization. In comparison, at 950 and 900 °C both the fraction of low angle boundaries and local misorientation was higher. At 1000 °C–3 × 10"−"3 s"−"1 the [111] direction was aligned along the compression axis, whereas at lower temperature of 900 °C and 3 × 10"−"3 s"−"1 it was the orientations close to [001]. - Highlights: • U-9Mo was deformed from 850 to 1000 °C and 3 × 10"−"3 to 1 s"−"1. • Strain rate sensitivity of 0.33 was observed at 1000 °C–3 × 10"−"3 s"−"1. • At 1000 °C the dominant texture was along the compression axis.

  15. Development and characterization of solidified forms for high-level wastes: 1978. Annual report

    International Nuclear Information System (INIS)

    Ross, W.A.; Mendel, J.E.

    1979-12-01

    Development and characterization of solidified high-level waste forms are directed at determining both process properties and long-term behaviors of various solidified high-level waste forms in aqueous, thermal, and radiation environments. Waste glass properties measured as a function of composition were melt viscosity, melt electrical conductivity, devitrification, and chemical durability. The alkali metals were found to have the greatest effect upon glass properties. Titanium caused a slight decrease in viscosity and a significant increase in chemical durability in acidic solutions (pH-4). Aluminum, nickel and iron were all found to increase the formation of nickel-ferrite spinel crystals in the glass. Four multibarrier advanced waste forms were produced on a one-liter scale with simulated waste and characterized. Glass marbles encapsulated in a vacuum-cast lead alloy provided improved inertness with a minimal increase in technological complexity. Supercalcine spheres exhibited excellent inertness when coated with pyrolytic carbon and alumina and put in a metal matrix, but the processing requirements are quite complex. Tests on simulated and actual high-level waste glasses continue to suggest that thermal devitrification has a relatively small effect upon mechanical and chemical durabilities. Tests on the effects radiation has upon waste forms also continue to show changes to be relatively insignificant. Effects caused by decay of actinides can be estimated to saturate at near 10 19 alpha-events/cm 3 in homogeneous solids. Actually, in solidified waste forms the effects are usually observed around certain crystals as radiation causes amorphization and swelling of th crystals

  16. Chemical characterization, leach, and adsorption studies of solidified low-level wastes

    International Nuclear Information System (INIS)

    Walter, M.B.; Serne, R.J.; Jones, T.L.; McLaurine, S.B.

    1986-12-01

    Laboratory and field leaching experiments are beig conducted by Pacific Northwest Laboratory (PNL) to investigate the performance of solidified low-level nuclear waste in a typical, arid, near-surface disposal site. Under PNL's Special Waste Form Lysimeters-Arid Program, a field test facility was constructed to monitor the leaching of commercial solidified waste. Laboratory experiments were conducted to investigate the leaching and adsorption characteristics of the waste forms in contact with soil. Liquid radioactive wastes solidified in cement, vinyl ester-styrene, and bitumen were obtained from commercial boiling water and pressurized water reactors, and buried in a field leaching facility on the Hanford site in southeastern Washington State. Batch leaching, soil column adsorption, and soil/waste form column experiments were conducted in the laboratory, using small-scale cement waste forms and Hanford site ground water. The purpose of these experiments is to evaluate the ability of laboratory leaching tests to predict leaching under actual field conditions and to determine which mechanisms (i.e., diffusion, solubility, adsorption) actually control the concentration of radionuclides in the soil surrounding the waste form. Chemical and radionuclide analyses performed on samples collected from the field and laboratory experiments indicate strong adsorption of /sup 134,137/Cs and 85 Sr onto the Hanford site sediment. Small amounts of 60 Co are leached from the waste forms as very mobile species. Some 60 Co migrated through the soil at the same rate as water. Chemical constituents present in the reactor waste streams also found at elevated levels in the field and laboratory leachates include sodium, sulfate, magnesium, and nitrate. Plausible solid phases that could be controlling some of the chemical and radionuclide concentrations in the leachate were identified using the MINTEQ geochemical computer code

  17. BASP1 is a transcriptional cosuppressor for the Wilms' tumor suppressor protein WT1

    DEFF Research Database (Denmark)

    Carpenter, Brian; Hill, Kathryn J; Charalambous, Marika

    2004-01-01

    The Wilms' tumor suppressor protein WT1 is a transcriptional regulator that plays a key role in the development of the kidneys. The transcriptional activation domain of WT1 is subject to regulation by a suppression region within the N terminus of WT1. Using a functional assay, we provide direct...... evidence that this requires a transcriptional cosuppressor, which we identify as brain acid soluble protein 1 (BASP1). WT1 and BASP1 associate within the nuclei of cells that naturally express both proteins. BASP1 can confer WT1 cosuppressor activity in transfection assays, and elimination of endogenous...

  18. Solidification structure and dispersoids in rapidly solidified Ti-Al-Sn-Zr-Er-B alloys

    International Nuclear Information System (INIS)

    Rowe, R.G.; Broderick, T.F.; Koch, E.F.; Froes, F.H.

    1986-01-01

    The microstructure of melt extracted and melt spun titanium alloys containing erbium and boron revealed a duplex solidification structure of columnar grains leading to equiaxed and dendritic structures near the free surface of melt extracted and melt spun alloys. The solidification structure was revealed by apparent boride segregation to cellular, interdendritic and grain boundaries. Precipitation of needle or lath-like TiB particles occurred adjacent to Er/sub 2/O/sub 3/ dispesoid particles in as-rapidly solidified ribbon

  19. Determination of performance criteria for high-level solidified nuclear waste

    Energy Technology Data Exchange (ETDEWEB)

    Heckman, R.A.; Holdsworth, T.

    1979-05-07

    To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste.

  20. The influence of interfacial energies and gravitational levels on the directionally solidified structures in hypermonotectic alloys

    Science.gov (United States)

    Andrews, J. B.; Curreri, P. A.; Sandlin, A. C.

    1988-01-01

    Various Cu-Pb-Al alloys were directionally solidified under 1-g conditions and alternating high-g/low-g conditions (achieved using NSAS's KC-135 aircraft) as a means of studying the influence of interfacial energies and gravitational levels on the resulting microstructures. Directional solidification of low Al content alloys was found to result in samples with coarser more irregular microstructures than in alloys with high Al contents under all the gravity conditions considered. Structures are correlated with interfacial energies, growth rates, and gravitational levels.

  1. Determination of performance criteria for high-level solidified nuclear waste

    International Nuclear Information System (INIS)

    Heckman, R.A.; Holdsworth, T.

    1979-01-01

    To minimize radiological risk from the operation of a waste management system, performance limits on volatilization, particulate dispersion, and dissolution characteristics of solidified high level waste must be specified. The results show clearly that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. Absolute values of expected risk are very sensitive to modeling assumptions. The transportation and interim storage operations appear to be most limiting in determining the performance characteristics required. The expected values of risk do not rely upon the repositories remaining intact over the potentially hazardous lifetime of the waste

  2. Nanostructured Titanium-10 wt% 45S5 Bioglass-Ag Composite Foams for Medical Applications

    Directory of Open Access Journals (Sweden)

    Karolina Jurczyk

    2015-03-01

    Full Text Available The article presents an investigation on the effectiveness of nanostructured titanium-10 wt% 45S5 Bioglass-1 wt% Ag composite foams as a novel class of antibacterial materials for medical applications. The Ti-based composite foams were prepared by the combination of mechanical alloying and a “space-holder” sintering process. In the first step, the Ti-10 wt% 45S5 Bioglass-1 wt% Ag powder synthesized by mechanical alloying and annealing mixed with 1.0 mm diameter of saccharose crystals was finally compacted in the form of pellets. In the next step, the saccharose crystals were dissolved in water, leaving open spaces surrounded by metallic-bioceramic scaffold. The sintering of the scaffold leads to foam formation. It was found that 1:1 Ti-10 wt% 45S5 Bioglass-1 wt% Ag/sugar ratio leads to porosities of about 70% with pore diameter of about 0.3–1.1 mm. The microstructure, corrosion resistance in Ringer’s solution of the produced foams were investigated. The value of the compression strength for the Ti-10 wt% 45S5 Bioglass-1 wt% Ag foam with 70% porosity was 1.5 MPa and the Young’s modulus was 34 MPa. Silver modified Ti-10 wt% 45S5 Bioglass composites possess excellent antibacterial activities against Staphylococcus aureus. Porous Ti-10 wt% 45S5 Bioglass-1 wt% foam could be a possible candidate for medical implants applications.

  3. Performance demonstration program plan for RCRA constituent analysis of solidified wastes

    International Nuclear Information System (INIS)

    1995-06-01

    Performance Demonstration Programs (PDPS) are designed to help ensure compliance with the Quality Assurance Objectives (QAOs) for the Waste Isolation Pilot Plant (WIPP). The PDPs are intended for use by the Department of Energy (DOE) Carlsbad Area Office (CAO) to assess and approve the laboratories and other measurement facilities supplying services for the characterization of WIPP TRU waste. The PDPs may also be used by CAO in qualifying laboratories proposing to supply additional analytical services that are required for other than waste characterization, such as WIPP site operations. The purpose of this PDP is to test laboratory performance for the analysis of solidified waste samples for TRU waste characterization. This performance will be demonstrated by the successful analysis of blind audit samples of simulated, solidified TRU waste according to the criteria established in this plan. Blind audit samples (hereinafter referred to as PDP samples) will be used as an independent means to assess laboratory performance regarding compliance with the QAOs. The concentration of analytes in the PDP samples will address levels of regulatory concern and will encompass the range of concentrations anticipated in actual waste characterization samples. Analyses that are required by the WIPP to demonstrate compliance with various regulatory requirements and which are included in the PDP must be performed by laboratories that demonstrate acceptable performance in the PDP. These analyses are referred to as WIPP analyses and the samples on which they are performed are referred to as WIPP samples for the balance of this document

  4. Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

    International Nuclear Information System (INIS)

    Donius, Amalie E.; Obbard, Rachel W.; Burger, Joan N.; Hunger, Philipp M.; Baker, Ian; Doherty, Roger D.; Wegst, Ulrike G.K.

    2014-01-01

    Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment

  5. EPICOR-II: a field leaching test of solidified radioactively loaded ion exchange resin

    International Nuclear Information System (INIS)

    Davis, E.C.; Marshall, D.S.; Todd, R.A.; Craig, P.M.

    1986-08-01

    As part of an ongoing research program investigating the disposal of radioactive solid wastes in the environment' the Oak Ridge National Laboratory (ORNL) is participating with Argonne National Laboratory, the Idaho National Engineering Laboratory, and the Nuclear Regulatory Commission in a study of the leachability of solidified EPICOR-II ion-exchange resin under simulated disposal conditions. To simulate disposal, a group of five 2-m 3 soil lysimeters has been installed in Solid Waste Storage Area Six at ORNL, with each lysimeter containing a small sample of solidified resin at its center. Two solidification techniques are being investigated: a Portland cement and a vinyl ester-styrene treatment. During construction, soil moisture temperature cells were placed in each lysimeter, along with five porous ceramic tubes for sampling water near the waste source. A meteorological station was set up at the study site to monitor climatic conditions (primarily precipitation and air temperature), and a data acquisition system was installed to keep daily records of these meteorological parameters as well as lysimeter soil moisture and temperature conditions. This report documents the first year of the long-term field study and includes discussions of lysimeter installation, calibration of soil moisture probes, installation of the site meteorological station, and the results of the first-quarter sampling for radionuclides in lysimeter leachate. In addition, the data collection and processing system developed for this study is documented, and the results of the first three months of data collection are summarized in Appendix D

  6. Study on metal material corrosion behavior of packaging of cement solidified form

    International Nuclear Information System (INIS)

    He Zhouguo; Lin Meiqiong; Fan Xianhua

    1997-01-01

    The corrosion behavior of A3 carbon steel is studied by the specimens that are exposed to atmosphere, embedded in cement solidified form or immersed in corrosion liquid. The corrosion rate is determined by mass change of the specimens. In order to compare the corrosion resistant performance of various coatings, the specimens painted with various material such as epoxide resin, propionic acid resin, propane ether resin and Ti-white paint are tested. The results of the tests show that corrosion rate of A3 carbon steel is less than 10 -3 mm·a -1 in the atmosphere and the cement solidified from, less than 0.1 mm·a -1 in the corrosion liquids, and pH value in the corrosion liquids also affect the corrosion rate of A3 carbon steel. The corrosion resistant performance of Ti-white paint is better than that of other paints. So, A3 carbon steel as packaging material can meet the requirements during storage

  7. Microstructural development in a rapidly solidified Al-Fe-V-Si alloy

    International Nuclear Information System (INIS)

    Park, W.J.; Baek, E.R.; Lee, Sunghak; Kim, N.J.

    1991-01-01

    TEM is used to investigate microstructural development in a rapidly solidified Al-Fe-V-Si alloy. The as-cast microstructure of a rapidly solidified Al-Fe-V-Si alloy was found to vary depending on casting conditions and also through the thickness of ribbon. For completely Zone A ribbon, intercellular phase consists of a microquasi-crystalline phase, while for the Zone A and Zone B mixed ribbon, it consists of a silicide phase. In either case, formation of globular particles of a cluster microquasi-crystalline phase is observed near the air side of the ribbon. Annealing study shows significant differences in the final microstructure depending on the initial status of the ribbon. Completely Zone A ribbon, whose microstructure is composed of a microquasi-crystalline phase, results in a very coarse microstructure after annealing as compared to the Zone A and Zone B mixed ribbon. This result has important implications for the development of high-performance elevated-temperature Al alloys. 12 refs

  8. Directionally solidified Al2O3/GAP eutectic ceramics by micro-pulling-down method

    Science.gov (United States)

    Cao, Xue; Su, Haijun; Guo, Fengwei; Tan, Xi; Cao, Lamei

    2016-11-01

    We reported a novel route to prepare directionally solidified (DS) Al2O3/GAP eutectic ceramics by micro-pulling-down (μ-PD) method. The eutectic crystallizations, microstructure characters and evolutions, and their mechanical properties were investigated in detail. The results showed that the Al2O3/GAP eutectic composites can be successfully fabricated through μ-PD method, possessed smooth surface, full density and large crystal size (the maximal size: φ90 mm × 20 mm). At the process of Diameter, the as-solidified Al2O3/GAP eutectic presented a combination of "Chinese script" and elongated colony microstructure with complex regular structure. Inside the colonies, the rod-type or lamellar-type eutectic microstructures with ultra-fine GAP surrounded by the Al2O3 matrix were observed. At an appropriate solidificational rate, the binary eutectic exhibited a typical DS irregular eutectic structure of "chinese script" consisting of interpenetrating network of α-Al2O3 and GAP phases without any other phases. Therefore, the interphase spacing was refined to 1-2 µm and the irregular microstructure led to an outstanding vickers hardness of 17.04 GPa and fracture toughness of 6.3 MPa × m1/2 at room temperature.

  9. Study on the barrier performance of molten solidified waste (I). Review of the performance assessment research

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Toshikatsu; Sakamoto, Yoshiaki; Nakayama, Shinichi; Yamaguchi, Tetsuji; Ogawa, Hiromichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-02-01

    Application of melting technique is thought as one of the effective methods to treatment of the waste from the view point of its homogeneity and waste volume reduction. Solidified products by melting are expected as potential candidates of engineered barrier in a repository due to the good properties for their stabilization of radionuclides and hazardous elements. However, the methodology of performance evaluation has not been estimated so far. In this report, a literature survey on the properties of molten solidified waste was performed. It is clarified that the leachability of waste elements such as Co or Sr in molten waste form would be controlled by the corrosion behaviors of iron or silica which are the matrix elements of the waste form. While, no investigations into the durability of waste form have performed so far. Also noticed that the research items on performance evaluation such as the leachability for long-lived radionuclides and durability of waste form would be necessary for the long-term barrier assessment on the disposal. (author)

  10. Testing of variables which affect stablity of cement solidified low-level waste

    International Nuclear Information System (INIS)

    Boris, G.F.

    1989-01-01

    This paper describes the test program undertaken to investigate variables which could affect the stability of cement solidified low-level waste and to evaluate the effect of these variables on certain tests prescribed in the Technical Position on Waste Form. The majority of the testing was performed on solidified undepleted bead resin, however, six additional waste types, suggested by the NRC, were tested. The tested variables included waste loading, immersion duration, depletion level, ambient cure duration, curing environment, immersion medium and waste type. Of these, lower waste loadings, longer ambient cures prior to testing and immersion in demineralized water versus simulated sea water and potable water resulted in higher compressive strengths for bead resin samples. Immersion times longer than 90 days did not affect the resin samples. Compressive strengths for other waste types varied depending upon the waste. The strengths of all waste types exceeded the minimum criterion by at least a factor of four, up to a factor of forty. The higher waste loadings exhibit strengths less than the lower waste loadings

  11. Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

    Energy Technology Data Exchange (ETDEWEB)

    Donius, Amalie E., E-mail: amalie.donius@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Obbard, Rachel W., E-mail: Rachel.W.Obbard@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Burger, Joan N., E-mail: ridge.of.the.ancients@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Hunger, Philipp M., E-mail: philipp.m.hunger@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Baker, Ian, E-mail: Ian.Baker@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Doherty, Roger D., E-mail: dohertrd@drexel.edu [Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Wegst, Ulrike G.K., E-mail: ulrike.wegst@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States)

    2014-07-01

    Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment.

  12. Detection of free liquid in cement-solidified radioactive waste drums using computed tomography

    International Nuclear Information System (INIS)

    Steude, J.S.; Tonner, P.D.

    1991-01-01

    Acceptance criteria for disposal of radioactive waste drums require that the cement-solidified material in the drum contain minimal free liquid after the cement has hardened. Free liquid is to be avoided because it may corrode the drum, escape and cause environmental contamination. The DOE has requested that a nondestructive evaluation method be developed to detect free liquid in quantities in excess of 0.5% by volume. This corresponds to about 1 liter in a standard 208 liter (55 gallon) drum. In this study, the detection of volumes of free liquid in a 57 cm (2 ft.) diameter cement-solidified drum is demonstrated using high-energy X-ray computed tomography (CT0. In this paper it is shown that liquid concentrations of simulated radioactive waste inside glass tubes imbedded in cement can easily be detected, even for tubes with inner diameters less than 2 mm (0.08 in.). Furthermore, it is demonstrated that tubes containing water and liquid concentrations of simulated radioactive waste can be distinguished from tubes of the same size containing air. The CT images were obtained at a rate of about 6 minutes per slice on a commercially available CT system using a 9 MeV linear accelerator source

  13. Experimental Study and Application of Inorganic Solidified Foam Filling Material for Coal Mines

    Directory of Open Access Journals (Sweden)

    Hu Wen

    2017-01-01

    Full Text Available Spontaneous combustion of residual coal in a gob due to air leakage poses a major risk to mining safety. Building an airtight wall is an effective measure for controlling air leakage. A new type of inorganic solidified foam-filled material was developed and its physical and chemical properties were analyzed experimentally. The compressive strength of this material increased with the amount of sulphoaluminate cement. With an increasing water–cement ratio, the initial setting time was gradually extended while the final setting time firstly shortened and then extended. The change in compressive strength had the opposite tendency. Additionally, as the foam expansion ratio increased, the solidification time tended to decrease but the compressive strength remained approximately constant. With an increase in foam production, the solidification time increased and the compressive strength decreased exponentially. The results can be used to determine the optimal material ratios of inorganic solidified foam-filled material for coal mines, and filling technology for an airtight wall was designed. A field application of the new material demonstrated that it seals crossheadings tightly, leaves no fissures, suppresses air leakage to the gob, and narrows the width of the spontaneous combustion and heat accumulation zone.

  14. The effect of grain size and cement content on index properties of weakly solidified artificial sandstones

    Science.gov (United States)

    Atapour, Hadi; Mortazavi, Ali

    2018-04-01

    The effects of textural characteristics, especially grain size, on index properties of weakly solidified artificial sandstones are studied. For this purpose, a relatively large number of laboratory tests were carried out on artificial sandstones that were produced in the laboratory. The prepared samples represent fifteen sandstone types consisting of five different median grain sizes and three different cement contents. Indices rock properties including effective porosity, bulk density, point load strength index, and Schmidt hammer values (SHVs) were determined. Experimental results showed that the grain size has significant effects on index properties of weakly solidified sandstones. The porosity of samples is inversely related to the grain size and decreases linearly as grain size increases. While a direct relationship was observed between grain size and dry bulk density, as bulk density increased with increasing median grain size. Furthermore, it was observed that the point load strength index and SHV of samples increased as a result of grain size increase. These observations are indirectly related to the porosity decrease as a function of median grain size.

  15. Microbially influenced degradation of cement-solidified low-level radioactive waste forms

    International Nuclear Information System (INIS)

    Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W. Jr.

    1996-01-01

    Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. This paper contains information on three groups of microoganisms that are associated with the degradation of cement materials: sulfur-oxidizing bacteria (Thiobacillus), nitrifying bacteria (Nitrosomonas and Nitrobacter), and heterotrophic bacteria, which produce organic acids. Preliminary work using laboratory- and vendor-manufactured, simulated waste forms exposed to thiobacilli has shown that microbiologically influenced degradation has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium was leached from the treated waste forms. Also, the surface pH of the treated specimens was decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 30 to 60 days of exposure

  16. Leaching test of bituminized waste and waste solidified by epoxy resin

    International Nuclear Information System (INIS)

    Yoshinaka, Kazuyuki; Sugaya, Atsushi; Onizawa, Toshikazu; Takano, Yugo; Kimura, Yukihiko

    2008-10-01

    About 30,000 bituminized waste drums and about 1800 drums of waste solidified by epoxy resin, generated from Tokai Reprocessing Plant, were stored in storage facilities. And study for disposal of these waste is performed. It was considered that radioactive nuclides and chemical components were released from these waste by contact of underground water, when disposed there waste. This paper is reported that result of leaching tests for these waste, done from 2003 to 2006. We've get precious knowledge and data, as follows. (1) In leaching tests for bituminized waste, it has detected iodine-129 peak, considered difficult too low energy gamma to detect. We've get data and knowledge of iodine-129 behavior first. Leached radioactivity for 50 days calculated by peak area was equal for about 40% and 100% of including radioactivity in bituminized waste sample. And we've get data of behavior of nitric acid ion and so on, important to study for disposal, in various condition of sample shape or leaching liquid temperature. (2) In leaching test for waste solidified by epoxy resin, we've get data of behavior of TBP, radionuclides and so on, important to study for disposal. Leached TBP was equal about 1% of including of sample. And we've get data of iodine-129 behavior, too. It was confirmed that leached iodine-129 was equal for about 60% and 100% of including sample, for 90 days. (author)

  17. Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys.

    Science.gov (United States)

    Hong, Jianping; Ma, Dexin; Wang, Jun; Wang, Fu; Sun, Baode; Dong, Anping; Li, Fei; Bührig-Polaczek, Andreas

    2016-11-16

    Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS) and single crystal (SX) hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

  18. Freckle Defect Formation near the Casting Interfaces of Directionally Solidified Superalloys

    Directory of Open Access Journals (Sweden)

    Jianping Hong

    2016-11-01

    Full Text Available Freckle defects usually appear on the surface of castings and industrial ingots during the directional solidification process and most of them are located near the interface between the shell mold and superalloys. Ceramic cores create more interfaces in the directionally solidified (DS and single crystal (SX hollow turbine blades. In order to investigate the location of freckle occurrence in superalloys, superalloy CM247 LC was directionally solidified in an industrial-sized Bridgman furnace. Instead of ceramic cores, Alumina tubes were used inside of the casting specimens. It was found that freckles occur not only on the casting external surfaces, but also appear near the internal interfaces between the ceramic core and superalloys. Meanwhile, the size, initial position, and area of freckle were investigated in various diameters of the specimens. The initial position of the freckle chain reduces when the diameter of the rods increase. Freckle area follows a linear relationship in various diameters and the average freckle fraction is 1.1% of cross sectional area of casting specimens. The flow of liquid metal near the interfaces was stronger than that in the interdendritic region in the mushy zone, and explained why freckle tends to occur on the outer or inner surfaces of castings. This new phenomenon suggests that freckles are more likely to occur on the outer or inner surfaces of the hollow turbine blades.

  19. Leachability of radionuclides from cement solidified waste forms produced at operating nuclear power plants

    International Nuclear Information System (INIS)

    Croney, S.T.

    1985-03-01

    This study determined the leachability indexes of radionuclides contained in solidified liquid wastes from operating nuclear power plants. Different sizes of samples of cement-solidified liquid wastes were collected from two nuclear power plants - a pressurized water reactor and a boiling water reactor - to correlate radionuclide leaching from small- and full-sized (55-gallon) waste forms. Diffusion-based model analysis (ANS 16.1) of measured radionuclide leach data from both small- and full-sized samples was performed and indicate that leach data from small samples can be used to determine leachability indexes for full-sizes waste forms. The leachability indexes for cesium, strontium, and cobalt isotopes were determined for waste samples from both plants according to the models used for ANS 16.1. The leachability indexes for the pressurized water reactor samples were 6.4 for cesium, 7.1 for strontium, and 10.4 for cobalt. Leachability indexes for the boiling water reactor samples were 6.5 for cesium, 8.6 for strontium, and 11.1 for cobalt

  20. Evaluating the freeze-thaw durability of portland cement-stabilized-solidified heavy metal waste using acoustic measurements

    International Nuclear Information System (INIS)

    El-Korchi, T.; Gress, D.; Baldwin, K.; Bishop, P.

    1989-01-01

    The use of stress wave propagation to assess freeze-thaw resistance of portland cement solidified/stabilized waste is presented. The stress wave technique is sensitive to the internal structure of the specimens and would detect structural deterioration independent of weight loss or visual observations. The freeze-thaw resistance of a cement-solidified cadmium waste and a control was evaluated. The control and cadmium wastes both showed poor freeze-thaw resistance. However, the addition of cadmium and seawater curing increased the resistance to more cycles of freezing and thawing. This is attributed to microstructural changes

  1. Long-term leach testing of solidified radioactive waste forms (International Standard Publication ISO 6961:1982)

    International Nuclear Information System (INIS)

    Stefanik, J.

    2001-01-01

    Processes are developed for the immobilization of radionuclides by solidification of radioactive wastes. The resulting solidification products are characterized by strong resistance to leaching aimed at low release rates of the radionuclides to the environment. To measure this resistance to leaching of the solidified materials: glass, glass-ceramics, bitumen, cement, concrete, plastics, a long-term leach test is presented. The long-term leach test is aimed at: a) the comparison of different kinds or compositions of solidified waste forms; b) the intercomparison between leach test results from different laboratories on one product; c) the intercomparison between leach test results on products from different processes

  2. Microstructural morphologies of slag based glass-ceramics nucleated with 5 wt% Cr{sub 2}O{sub 3} and 5 wt% Cr{sub 2}O{sub 3} + 5 wt% TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Oevecoglu, M.L.; Oezkal, B. [Istanbul Technical Univ. (Turkey). Dept. of Metallurgical and Materials Enginering; Catakli, E. [Mimar Sinan Univ., Istanbul (Turkey). Faculty of Science and Literature; Erkmen, Z.E. [Istnabul Univ. (Turkey). Dept. of Metallurgical Engineering

    2002-07-01

    Glass-ceramic materials were developed from the blast-furnace slags by mixing 5 wt% Cr{sub 2}O{sub 3} and 5 wt% Cr{sub 2}O{sub 3} + 5 wt% TiO{sub 2}. The samples were nucleated for 18 h at 780 C and crystallized for 20 min. at 905 C, respectively. SEM and SEM/EDS investigations revealed the presence of clover-shaped TiO{sub 2} particles in the glassy matrix of the sample nucleated with 5 wt% Cr{sub 2}O{sub 3} + 5 wt% TiO{sub 2} and polygonal-shaped Cr{sub 2}O{sub 3} platelets for both samples. XRD scans revealed the presence of akermanite (2CaO.MgO.2SiO{sub 2}) and gehlenite (2CaO.Al{sub 2}O{sub 3}.SiO{sub 2}) peaks indicating the existence of the mellilite solid solution for the crystallized glass-ceramic samples. (orig.)

  3. Analysis of aquifer tests conducted in boreholes USW WT-10, UE-25 WT No. 12, and USW SD-7, 1995-96, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    O'Brien, G.M.

    1997-01-01

    Single-borehole aquifer tests were conducted in three boreholes in the Yucca Mountain area between March 1995 and January 1996 to obtain estimates of borehole specific capacity and aquifer transmissivity. Analysis of aquifer testing in borehole USW SD-7 also resulted in an estimate of reservoir volume. Aquifer-test data were analyzed with the Cooper and Jacob straight-line method, two modified Theis nonequilibrium equation solutions, and a modified reservoir-limit solution. The highest estimates of transmissivity were in borehole USW WT-10, completed in the Topopah Spring Tuff. Mean transmissivity, based on the results of three drawdown tests, was 1,600 meters squared per day. Mean specific capacity in borehole USW WT-10 after 5 hours of pumping was 1,100 meters squared per day, and was estimated to be 740 meters squared per day after 24 hours of pumping. Aquifer testing in borehole UE-25 WT No. 12 appeared to be significantly affected by well losses. A mean transmissivity of 7 meters squared per day was obtained on the basis of analysis of three drawdown tests in borehole UE-25 WT No. 12. Mean specific capacity in borehole UE-25 WT No. 12, after 24 hours of pumping, was 7 meters squared per day. Borehole UE-25 WT No. 12 seemed to be producing water from fractures that could provide only a limited amount of water to the borehole

  4. Influence of the UV Radiation on Rhodamine WT Fluorescence in Water Samples

    OpenAIRE

    , L. Kola; , P. Lazo

    2016-01-01

    The şuorescence ability of Rhodamine WT enables its using as artiŞcial tracer in the water system studies. The problem is dealt with in relation to applying Rhodamine WT (RhWT) to trace and determine water movements within the karstic system and underground waters. Rhodamine WT has been used as an artiŞcial tracer for the Şrst times in our country on Mali me Gropa system study (2002). UV radiation may induce photochemical decomposition of the dye which can cause large measurement errors on me...

  5. Expression of the Wilms' tumor gene WT1 in the murine urogenital system.

    Science.gov (United States)

    Pelletier, J; Schalling, M; Buckler, A J; Rogers, A; Haber, D A; Housman, D

    1991-08-01

    The Wilms' tumor gene WT1 is a recessive oncogene that encodes a putative transcription factor implicated in nephrogenesis during kidney development. In this report we analyze expression of WT1 in the murine urogenital system. WT1 is expressed in non-germ-cell components of the testis and ovaries in both young and adult mice. In situ mRNA hybridization studies demonstrate that WT1 is expressed in the granulosa and epithelial cells of ovaries, the Sertoli cells of the testis, and in the uterine wall. In addition to the 3.1-kb WT1 transcript detected by Northern blotting of RNA from kidney, uterus, and gonads, there is an approximately 2.5-kb WT1-related mRNA species in testis. The levels of WT1 mRNA in the gonads are among the highest observed, surpassing amounts detected in the embryonic kidney. During development, these levels are differentially regulated, depending on the sexual differentiation of the gonad. Expression of WT1 mRNA in the female reproductive system does not fluctuate significantly from days 4 to 40 postpartum. In contrast, WT1 mRNA levels in the tesis increase steadily after birth, reaching their highest expression levels at day 8 postpartum and decreasing slightly as the animal matures. Expression of WT1 in the gonads is detectable as early as 12.5 days postcoitum (p.c.). As an initial step toward exploring the tissue-specific expression of WT1, DNA elements upstream of WT1 were cloned and sequenced. Three putative transcription initiation sites, utilized in testis, ovaries, and uterus, were mapped by S1 nuclease protection assays. The sequences surrounding these sites have a high G + C content, and typical upstream CCAAT and TATAA boxes are not present. These studies allowed us to identify the translation initiation site for WT1 protein synthesis. We have also used an epitope-tagging protocol to demonstrate that WT1 is a nuclear protein, consistent with its role as a transcription factor. Our results demonstrate regulation of WT1 expression

  6. Evaluation of leaching behavior and immobilization of zinc in cement-based solidified products

    Directory of Open Access Journals (Sweden)

    Krolo Petar

    2012-01-01

    Full Text Available This study has examined leaching behavior of monolithic stabilized/solidified products contaminated with zinc by performing modified dynamic leaching test. The effectiveness of cement-based stabilization/solidification treatment was evaluated by determining the cumulative release of Zn and diffusion coefficients, De. The experimental results indicated that the cumulative release of Zn decreases as the addition of binder increases. The values of the Zn diffusion coefficients for all samples ranged from 1.210-8 to 1.1610-12 cm2 s-1. The samples with higher amounts of binder had lower De values. The test results showed that cement-based stabilization/solidification treatment was effective in immobilization of electroplating sludge and waste zeolite. A model developed by de Groot and van der Sloot was used to clarify the controlling mechanisms. The controlling leaching mechanism was found to be diffusion for samples with small amounts of waste material, and dissolution for higher waste contents.

  7. Processing method of radiation concrete waste and manufacturing method for radioactive waste solidifying filling mortar

    International Nuclear Information System (INIS)

    Sukekiyo, Mitsuaki; Okamoto, Masamichi

    1998-01-01

    Radioactive concrete wastes are crushed and pulverized. Fine solid granular materials caused by the pulverization are classified and the grain size is controlled so that the maximum grain size is 2.5mm, with the grains having a grain size of up to 0.15mm being up to 30% by weight to form fine aggregates. Separated and recovered fine concrete powders are classified and the size of the powder is controlled within a range of from 3,000 to 15,000cm 2 /g which is smaller than cement particles to form fine powders having a stable quality suitable as a mixing agent. The fine aggregates and the mixing agent are mixed to form a filling mortar (filler) for solidifying radioactive wastes. The filling mortar is filled together with other radioactive wastes in a drum to form a waste body in a drum. With such a constitution, crushed radioactive concrete wastes can be reutilized completely. (I.N.)

  8. Retrievable surface storage: interim storage of solidified high-level waste

    International Nuclear Information System (INIS)

    LaRiviere, J.R.; Nelson, D.C.

    1976-01-01

    Studies have been conducted on retrievable-surface-storage concepts for the interim storage of solidified high-level wastes. These studies have been reviewed by the Panel on Engineered Storage, convened by the Committee on Radioactive Waste Management of the National Research Council-National Academy of Sciences. The Panel has concluded that ''retrievable surface storage is an acceptable interim stage in a comprehensive system for managing high-level radioactive wastes.'' The scaled storage cask concept, which was recommended by the Panel on Engineered Storage, consists of placing a canister of waste inside a carbon-steel cask, which in turn is placed inside a thick concrete cylinder. The waste is cooled by natural convection air flow through an annulus between the cask and the inner wall of the concrete cylinder. The complete assembly is placed above ground in an outdoor storage area

  9. Solidified structure of thin-walled titanium parts by vertical centrifugal casting

    Directory of Open Access Journals (Sweden)

    Wu Shiping

    2011-05-01

    Full Text Available The solidified structure of the thin-walled and complicated Ti-6Al-4V castings produced by the vertical centrifugal casting process was studied in the present work. The results show that the wall thickness of the section is featured with homogeneously distributed fine equiaxial grains, compared with the microstructure of the thick-walled section. The grain size of the castings has a tendency to decrease gradually with the increasing of the centrifugal radius. The inter-lamellar space in thick-walled casting parts is bigger than that of the thin-walled parts, and the profile of inter-lamellar space is not susceptible to the centrifugal radius.

  10. On oscillatory microstructure during cellular growth of directionally solidified Sn-36at.%Ni peritectic alloy.

    Science.gov (United States)

    Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie

    2016-04-12

    An oscillatory microstructure has been observed during deep-cellular growth of directionally solidified Sn-36at.%Ni hyperperitectic alloy containing intermetallic compounds with narrow solubility range. This oscillatory microstructure with a dimension of tens of micrometers has been observed for the first time. The morphology of this wave-like oscillatory structure is similar to secondary dendrite arms, and can be observed only in some local positions of the sample. Through analysis such as successive sectioning of the sample, it can be concluded that this oscillatory microstructure is caused by oscillatory convection of the mushy zone during solidification. And the influence of convection on this oscillatory microstructure was characterized through comparison between experimental and calculations results on the wavelength. Besides, the change in morphology of this oscillatory microstructure has been proved to be caused by peritectic transformation during solidification. Furthermore, the melt concentration increases continuously during solidification of intermetallic compounds with narrow solubility range, which helps formation of this oscillatory microstructure.

  11. Annual report on the development and characterization of solidified forms for nuclear wastes, 1979

    International Nuclear Information System (INIS)

    Chick, L.A.; McVay, G.L.; Mellinger, G.B.; Roberts, F.P.

    1980-12-01

    Development and characterization of solidified nuclear waste forms is a major continuing effort at Pacific Northwest Laboratory. Contributions from seven programs directed at understanding chemical composition, process conditions, and long-term behaviors of various nuclear waste forms are included in this report. The major findings of the report are included in extended figure captions that can be read as brief technical summaries of the research, with additional information included in a traditional narrative format. Waste form development proceeded on crystalline and glass materials for high-level and transuranic (TRU) wastes. Leaching studies emphasized new areas of research aimed at more basic understanding of waste form/aqueous solution interactions. Phase behavior and thermal effects research included studies on crystal phases in defense and TRU waste glasses and on liquid-liquid phase separation in borosilicate waste glasses. Radiation damage effects in crystals and glasses from alpha decay and from transmutation are reported

  12. Experimental study of directionally solidified ferromagnetic shape memory alloy under multi-field coupling

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuping, E-mail: zhuyuping@126.com [Institute of Geophysics, China Earthquake Administration, Beijing 100081 (China); Chen, Tao; Teng, Yao [Faculty of Civil Engineering and Mechanics, Jiangsu University, Zhenjiang 212013 (China); Liu, Bingfei [Airport College, Civil Aviation University of China, Tianjin 300300 (China); Xue, Lijun [Tianjin Key Laboratory of the Design and Intelligent Control of the Advanced Mechatronical System, School of Mechanical Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2016-11-01

    Directionally solidified, polycrystalline Ni–Mn–Ga is studied in this paper. The polycrystalline Ni–Mn–Ga samples were cut at different angles to solidification direction. The magnetic field induced strain under constant stress and the temperature-induced strain under constant magnetic field during the loading–unloading cycle were measured. The experimental results show that the mechanical behavior during the loading–unloading cycle of the material is nonlinear and anisotropic. Based on the experimental results, the effects of multi-field coupling factors, such as stress, magnetic field, temperature and cutting angle on the mechanical behaviors were analyzed. Some useful conclusions were obtained, which will provide guidance for practical applications. - Highlights: • The magnetic-induced strains in different directions are tested. • The temperature-induced strains in different directions are tested. • The effects of coupling factors on directional solidification samples are studied.

  13. The Characterization of Filtration Waste Solidified Product from Baghouse Filter of the Incineration Process

    International Nuclear Information System (INIS)

    Sutoto

    2000-01-01

    To increase of the safety, quality and to easy maintenance of the incinerator media of bag house filter, coating of the surface filter media by CaCO 3 powder were done. In the incinerator process, the CaCO 3 powder will scrub of fly ash as secondary waste. And finally, both of the secondary waste and CaCO 3 will immobilized by cement matrix. The research has an objective to study and characterizing of the CaCO 3 as secondary waste on their cemented product. The research were done on block samples with content of CaCO 3 and the properties characterized by compressive strength and density. From this research known that on their solidified, each quantity of CaCO 3 will be impact to decreasing of the quality cementation product. The optimum formula for solidification of bag house filter scrubbed is CaCO 3 : cement: water is 3 : 10 : 7. (author)

  14. Relationship between critical current properties and microstructure in cylindrical RE123 melt-solidified bulks

    International Nuclear Information System (INIS)

    Nakashima, T.; Shimoyama, J.; Honzumi, M.; Tazaki, Y.; Horii, S.; Kishio, K.

    2005-01-01

    We report the synthesis of cylindrical melt-solidified bulks in REBa 2 Cu 3 O y (RE = Sm, Gd, Dy, Ho, Y and Er), and their critical current properties and microstructures of the a- and the c-growth regions. It was found from the microstructure analysis that the volume fractions of RE211 particles in the c-growth region were always lower than those in the a-growth region. Moreover, those in the c-growth region were increased with distance from the seed crystal. Interestingly, the second peak effects in J c -B curves were prominently enhanced for the c-growth region. J c values at zero field for the c-growth region through the appropriate oxygen post-annealing reached approximately 95 kA cm -2 for RE = Ho, Dy and Y

  15. Phase composition of rapidly solidified Ag-Sn-Cu dental alloys

    International Nuclear Information System (INIS)

    Lecong Dzuong; Do Minh Nghiep; Nguyen van Dzan; Cao the Ha

    1996-01-01

    The phase composition of some rapidly solidified Ag-Sn-Cu dental alloys with different copper contents (6.22 wtpct) has been studied by XRD, EMPA and optical microscopy. The samples were prepared from melt-spun ribbons. The microstructure of the as-quenched ribbons was microcrystalline and consisted of the Ag sub 3 Sn, Ag sub 4 Sn, Cu sub 3 Sn and Cu sub 3 Sn sub 8 phases. Mixing with mercury (amalgamation) led to formation of the Ag sub 2 Hg sub 3, Sn sub 7 Hg and Cu sub 6 Sn sub 5 phases. The amount of copper atoms in the alloys played an important role in phase formation in the amalgams

  16. Solute redistribution and Rayleigh number in the mushy zone during directional solidifi cation of Inconel 718

    Directory of Open Access Journals (Sweden)

    Wang Ling

    2009-08-01

    Full Text Available The interdendritic segregation along the mushy zone of directionally solidifi ed superalloy Inconel 718 has been measured by scanning electron microscope (SEM and energy dispersion analysis spectrometry (EDAXtechniques and the corresponding liquid composition profile was presented. The liquid density and Rayleigh number (Ra profi les along the mushy zone were calculated as well. It was found that the liquid density difference increased from top to bottom in the mushy zone and there was no density inversion due to the segregation of Nb and Mo. However carbide formation in the freezing range and the preferred angle of the orientated dendrite array could prompt the fl uid fl ow in the mushy zone although there was no liquid density inversion. The largest relative Rayleigh number appeared at 1,326 篊 for Inconel 718 where the fl uid fl ow most easily occurred.

  17. Microstructure and property of directionally solidified Ni-Si hypereutectic alloy

    Science.gov (United States)

    Cui, Chunjuan; Tian, Lulu; Zhang, Jun; Yu, Shengnan; Liu, Lin; Fu, Hengzhi

    2016-03-01

    This paper investigates the influence of the solidification rate on the microstructure, solid/liquid interface, and micro-hardness of the directionally solidified Ni-Si hypereutectic alloy. Microstructure of the Ni-Si hypereutectic alloy is refined with the increase of the solidification rate. The Ni-Si hypereutectic composite is mainly composed of α-Ni matrix, Ni-Ni3Si eutectic phase, and metastable Ni31Si12 phase. The solid/liquid interface always keeps planar interface no matter how high the solidification rate is increased. This is proved by the calculation in terms of M-S interface stability criterion. Moreover, the Ni-Si hypereutectic composites present higher micro-hardness as compared with that of the pure Ni3Si compound. This is caused by the formation of the metastable Ni31Si12 phase and NiSi phase during the directional solidification process.

  18. Importance of microscopy in durability studies of solidified and stabilized contaminated soils

    Science.gov (United States)

    Klich, I.; Wilding, L.P.; Drees, L.R.; Landa, E.R.

    1999-01-01

    Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical, thermal, or biological means. Despite the increased use of S/S technologies, little research has been conducted on the weathering and degradation of solidified and stabilized wastes once the treated materials have been buried. Published data to verify the performance and durability of landfilled treated wastes over time are rare. In this preliminary study, optical and electron microscopy (scanning electron microscopy [SEM], transmission electron microscopy [TEM] and electron probe microanalyses [EPMA]) were used to evaluate weathering features associated with metal-bearing contaminated soil that had been solidified and stabilized with Portland cement and subsequently buried on site, stored outdoors aboveground, or achieved in a laboratory warehouse for up to 6 yr. Physical and chemical alteration processes identified include: freeze-thaw cracking, cracking caused by the formation of expansive minerals such as ettringite, carbonation, and the movement of metals from waste aggregates into the cement micromass. Although the extent of degradation after 6 yr is considered slight to moderate, results of this study show that the same environmental concerns that affect the durability of concrete must be considered when evaluating the durability and permanence of the solidification and stabilization of contaminated soils with cement. In addition, such evaluations cannot be based on leaching and chemical analyses alone. The use of all levels of microscopic analyses must be incorporated into studies of the long-term performance of S/S technologies.Solidification/stabilization (S/S) is recognized by the U.S. EPA as a best demonstrated available technology for the containment of contaminated soils and other hazardous wastes that cannot be destroyed by chemical

  19. 3D observation of the solidified structures by x-ray micro computerized tomography

    International Nuclear Information System (INIS)

    Yasuda, Hideyuki; Ohnaka, Itsuo; Tsuchiyama, Akira; Nakano, Tsukasa; Uesugi, Kentaro

    2003-01-01

    The high flux density of the monochromatized and well-collimated X-ray and the high-resolution detector provide a new 3D observation tool for microstructures of metallic alloys and ceramics. The X-ray micro computerized tomography in BL47XU of SPring-8 (SP-μCT) was applied to observe microstructures produced through the eutectic reaction for Sn-based alloys and an Al 2 O 3 -Y 2 O 3 oxide system. The constituent phases in the eutectic structures were three-dimensionally identified, in which the lamellar spacing ranged from several to 10 μm. Since the 3D structure of the unidirectionally solidified specimens contains history of the eutectic structure formation, the 3D structure obtained by SP-μCT gives useful information to consider the microstructure evolution. (author)

  20. Experimental study on the leaching of radioactive materials from radioactive wastes solidified in cement into sea water. Part 2

    International Nuclear Information System (INIS)

    Hatta, H.; Ono, H.; Nagakura, T.; Machida, T.; Seki, T.; Maki, Y.

    Results are presented from the study on leachability of 60 Co and 137 Cs from BWR concentrated wastes that had been solidified in cement. The leachability of 60 Co is very small compared to that of 137 Cs and varies greatly with the type of leaching medium. The effect of duration of immersion on leachability is comparatively large

  1. A Laboratory Screening Study On The Use Of Solidifiers As A Response Tool To Remove Crude Oil Slicks On Seawater

    Science.gov (United States)

    The effectiveness of five solidifiers to remove Prudhoe Bay crude oil from artificial seawater in the laboratory was determined by ultraviolet-visible spectroscopy (UV-VIS) and gas chromatography/mass spectrometry (GC/MS). The performance of the solidifers was determined by US-V...

  2. Formation of metastable phases and nanocomposite structures in rapidly solidified Al-Fe alloys

    International Nuclear Information System (INIS)

    Nayak, S.S.; Chang, H.J.; Kim, D.H.; Pabi, S.K.; Murty, B.S.

    2011-01-01

    Highlights: → Structures of nanocomposites in rapidly solidified Al-Fe alloys were investigated. → Nanoquasicrystalline, amorphous and intermetallics phases coexist with α-Al. → Nanoquasicrystalline phase was observed for the first time in the dilute Al alloys. → Thermodynamic driving force plays dominant role in precipitation of Fe-rich phases. → High hardness (3.57 GPa) was observed for nanocomposite of Al-10Fe alloy. - Abstract: In the present work the structure and morphology of the phases of nanocomposites formed in rapidly solidified Al-Fe alloys were investigated in details using analytical transmission electron microscopy and X-ray diffraction. Nanoquasicrystalline phases, amorphous phase and intermetallics like Al 5 Fe 2 , Al 13 F 4 coexisted with α-Al in nanocomposites of the melt spun alloys. It was seen that the Fe supersaturation in α-Al diminished with the increase in Fe content and wheel speed indicating the dominant role of the thermodynamic driving force in the precipitation of Fe-rich phases. Nanoquasicrystalline phases were observed for the first time in the dilute Al alloys like Al-2.5Fe and Al-5Fe as confirmed by high resolution TEM. High hardness (3.57 GPa) was measured in nanocomposite of Al-10Fe alloy, which was attributed to synergistic effect of solid solution strengthening due to high solute content (9.17 at.% Fe), dispersion strengthening by high volume fraction of nanoquasicrystalline phase; and Hall-Petch strengthening from finer cell size (20-30 nm) of α-Al matrix.

  3. Surface free energy of polypropylene and polycarbonate solidifying at different solid surfaces

    International Nuclear Information System (INIS)

    Chibowski, Emil; Terpilowski, Konrad

    2009-01-01

    Advancing and receding contact angles of water, formamide, glycerol and diiodomethane were measured on polypropylene (PP) and polycarbonate (PC) sample surfaces which solidified at Teflon, glass or stainless steel as matrix surfaces. Then from the contact angle hystereses (CAH) the apparent free energies γ s tot of the surfaces were evaluated. The original PP surface is practically nonpolar, possessing small electron donor interaction (γ s - =1.91mJ/m 2 ), as determined from the advancing contact angles of these liquids. It may result from impurities of the polymerization process. However, it increases up to 8-10 mJ/m 2 for PP surfaces contacted with the solids. The PC surfaces both original and modified show practically the same γ s - =6.56.7mJ/m 2 . No electron acceptor interaction is found on the surfaces. The γ s tot of modified PP and PC surfaces depend on the kind of probe liquid and contacted solid surface. The modified PP γ s tot values determined from CAH of polar liquids are greater than that of original surface and they increase in the sequence: Teflon, glass, stainless steel surface, at which they solidified. No clear dependence is observed between γ s tot and dielectric constant or dipole moment of the polar probe liquids. The changes in γ s tot of the polymer surfaces are due to the polymer nature and changes in its surface structure caused by the structure and force field of the contacting solid. It has been confirmed by AFM images.

  4. Leachability and heavy metal speciation of 17-year old stabilised/solidified contaminated site soils

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fei, E-mail: fwtiffany@gmail.com [Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom); Wang, Hailing, E-mail: wanghailing@njtech.edu.cn [College of Environment, Nanjing Tech University, Nanjing 210009 (China); Al-Tabbaa, Abir, E-mail: aa22@cam.ac.uk [Department of Engineering, University of Cambridge, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)

    2014-08-15

    Highlights: • The effectiveness of the cement-based S/S at 17 years in West Drayton site is still satisfactory. • Major leaching of Cu, Zn, Ni, Cd and Pb in all mixes took place in the Fe/Mn oxides phase. • The hydration process has been fully completed and further carbonation took place at 17 years. • Microstructure analyses show that unreacted PFA exists. - Abstract: The long-term leachability, heavy metal speciation transformation and binding mechanisms in a field stabilised/solidified contaminated soil (made ground) from West Drayton site were recently investigated following in situ auger mixing treatment with a number of cement-based binders back in 1996. Two batch leaching tests (TCLP and BS EN 12457) and a modified five step sequential extraction procedure along with X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses were employed for the testing of the 17-year-old field soil. The results of batch leaching tests show that the treatment employed remained effective at 17 years of service time, with all BS EN 12457 test samples and most of TCLP test samples satisfied drinking water standards. Sequential extraction results illustrate that the leaching of Cu, Ni, Zn, Pb and Cd in all mixes mainly occurred at the Fe/Mn phase, ranging from 43% to 83%. Amongst the five metals tested, Ni was the most stable with around 40% remained in the residual phase for all the different cement-based binder stabilised/solidified samples. XRD and SEM analyses show that the hydration process has been fully completed and further carbonation took place. In summary, this study confirms that such cement-based stabilisation/solidification (S/S) treatment can achieve satisfactory durability and thus is a reliable technique for long-term remediation of heavy metal contaminated soil.

  5. Study on Magnesium in Rainwater and Fertilizer Infiltration to Solidified Peat

    Science.gov (United States)

    Tajuddin, S. A. M.; Rahman, J. A.; Mohamed, R. M. S. R.

    2018-04-01

    Magnesium is a component of several primary and secondary minerals in the soil which are essentially insoluble for agricultural purpose. The presence of water infiltrate in the soil allows magnesium to dissolve together into the groundwater. In fertilizers, magnesium is categorized as secondary macronutrient which supplies food and encouraging for plants growth. The main objective of this study was to determine the concentration of magnesium in fibric peat when applied the solidification under different conditions. Physical model was used as a mechanism for the analysis of the experimental data using a soil column as an equipment to produce water leaching. In this investigation, there were four outlets in the soil column which were prepared from the top of the column to the bottom with the purpose of identifying the concentration of magnesium for each soil level. The water leaching of each outlet was tested using atomic absorption spectroscopy (AAS). The results obtained showed that the highest concentrations of magnesium for flush and control condition at outlet 4 was 12.50 ppm and 1.29 ppm respectively. Similarly, fibric with solidified peat under rainwater recorded the highest value of 3.16 at outlet 1 for wet condition while for dry condition at outlet 4 of 1.33 ppm. However, the difference in fibric with solidified peat under rainwater and fertilizer condition showed that the highest value for the wet condition was achieved at outlet 1 with 5.43 ppm while highest value of 1.26 ppm was obtained for the dry condition at the outlet 4. It was concluded that the outlets in the soil column gave a detailed analysis of the concentration of magnesium in the soil which was influenced by the environmental conditions.

  6. Structures of native and affinity-enhanced WT1 epitopes bound to HLA-A*0201: Implications for WT1-based cancer therapeutics

    Energy Technology Data Exchange (ETDEWEB)

    Borbulevych, Oleg Y.; Do, Priscilla; Baker, Brian M. (Notre)

    2010-09-07

    Presentation of peptides by class I or class II major histocompatibility complex (MHC) molecules is required for the initiation and propagation of a T cell-mediated immune response. Peptides from the Wilms Tumor 1 transcription factor (WT1), upregulated in many hematopoetic and solid tumors, can be recognized by T cells and numerous efforts are underway to engineer WT1-based cancer vaccines. Here we determined the structures of the class I MHC molecule HLA-A*0201 bound to the native 126-134 epitope of the WT1 peptide and a recently described variant (R1Y) with improved MHC binding. The R1Y variant, a potential vaccine candidate, alters the positions of MHC charged side chains near the peptide N-terminus and significantly reduces the peptide/MHC electrostatic surface potential. These alterations indicate that the R1Y variant is an imperfect mimic of the native WT1 peptide, and suggest caution in its use as a therapeutic vaccine. Stability measurements revealed how the R1Y substitution enhances MHC binding affinity, and together with the structures suggest a strategy for engineering WT1 variants with improved MHC binding that retain the structural features of the native peptide/MHC complex.

  7. Effect of Ag additions on the β phase formation reaction in the Cu–9 wt.%Al–6 wt.%Mn alloy

    Energy Technology Data Exchange (ETDEWEB)

    Adorno, A.T., E-mail: atadorno@iq.unesp.br [Departamento de Físico-Química, Instituto de Química, UNESP, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil); Carvalho, T.M. [Departamento de Físico-Química, Instituto de Química, UNESP, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil); Silva, R.A.G. [Departamento de Ciências Exatas e da Terra, UNIFESP, 09972-270 Diadema, SP (Brazil); Santos, C.M.A.; Magdalena, A.G. [Departamento de Físico-Química, Instituto de Química, UNESP, Caixa Postal 355, 14801-970 Araraquara, SP (Brazil)

    2015-09-15

    Highlights: • The results suggest a multi-step process involving reversible reactions. • Ag solubilizes preferably at the Cu matrix. • Ag additions decrease the activation energy for the process. - Abstract: The influence of 4 and 5 wt.%Ag additions on the kinetics of β [T{sub 7}-(CuMn){sub 3}Al] phase formation reaction in the Cu–9 wt.%Al–6 wt.%Mn alloy was studied using differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and scanning electron microscopy (SEM). The results indicate that the conversion dependence of the activation energy has a descending shape, suggesting a multi-step process involving reversible reactions. The presence of Ag facilitates the formation of the β phase. The results also showed that the Ag precipitates formation includes the dissolution of Mn and Al atoms, thus decreasing the partial fraction of these elements available to react.

  8. Osr1 Interacts Synergistically with Wt1 to Regulate Kidney Organogenesis.

    Directory of Open Access Journals (Sweden)

    Jingyue Xu

    Full Text Available Renal hypoplasia is a common cause of pediatric renal failure and several adult-onset diseases. Recent studies have associated a variant of the OSR1 gene with reduction of newborn kidney size and function in heterozygotes and neonatal lethality with kidney defects in homozygotes. How OSR1 regulates kidney development and nephron endowment is not well understood, however. In this study, by using the recently developed CRISPR genome editing technology, we genetically labeled the endogenous Osr1 protein and show that Osr1 interacts with Wt1 in the developing kidney. Whereas mice heterozygous for either an Osr1 or Wt1 null allele have normal kidneys at birth, most mice heterozygous for both Osr1 and Wt1 exhibit defects in metanephric kidney development, including unilateral or bilateral kidney agenesis or hypoplasia. The developmental defects in the Osr1+/-Wt1+/- mouse embryos were detected as early as E10.5, during specification of the metanephric mesenchyme, with the Osr1+/-Wt1+/- mouse embryos exhibiting significantly reduced Pax2-positive and Six2-positive nephron progenitor cells. Moreover, expression of Gdnf, the major nephrogenic signal for inducing ureteric bud outgrowth, was significantly reduced in the metanephric mesenchyme in Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- littermates. By E11.5, as the ureteric buds invade the metanephric mesenchyme and initiate branching morphogenesis, kidney morphogenesis was significantly impaired in the Osr1+/-Wt1+/- embryos in comparison with the Osr1+/- or Wt1+/- embryos. These results indicate that Osr1 and Wt1 act synergistically to regulate nephron endowment by controlling metanephric mesenchyme specification during early nephrogenesis.

  9. Evidence that WT1 mutations in Denys-Drash syndrome patients may act in a dominant-negative fashion

    NARCIS (Netherlands)

    Little, M. H.; Williamson, K. A.; Mannens, M.; Kelsey, A.; Gosden, C.; Hastie, N. D.; van Heyningen, V.

    1993-01-01

    The triad of nephropathy, partial gonadal dysgenesis and Wilms' tumour (WT) is known as Denys-Drash syndrome (DDS). The WT predisposition gene WT1, which plays a vital role in both genital and renal development, is known to be mutated in DDS patients. The WT1 mutations in these patients are

  10. WT1 vaccination in acute myeloid leukemia: new methods of implementing adoptive immunotherapy.

    Science.gov (United States)

    Rein, Lindsay A M; Chao, Nelson J

    2014-03-01

    The Wilms tumor 1 (WT1) gene was originally identified as a tumor suppressor gene that, when mutated, would lead to the development of pediatric renal tumors. More recently, it has been determined that WT1 is overexpressed in 90% of patients with acute myeloid leukemia (AML) and is mutated in approximately 10% of AML patients. WT1 plays a role in normal hematopoiesis and, in AML specifically, it has oncogenic function and plays an important role in cellular proliferation and differentiation. The ubiquity of WT1 in leukemia has lead to the development of vaccines aimed at employing the host immune system to mount a T-cell response to a known antigen. In this evaluation, the authors discuss the role of WT1 in normal hematopoiesis as well as in the development of hematologic malignancies. Furthermore, the authors discuss the data supporting the development of WT1 vaccines, and the clinical trials supporting their use in patients with acute leukemia. Several small trials have been conducted which support the safety and efficacy of this therapy, although larger trials are certainly warranted. In the authors' opinion, the WT1 vaccination has potential in terms of its application as an adjuvant therapy for patients with AML who are at high risk of relapse or who have detectable minimal residual disease after initial standard therapy.

  11. Comparison of electrochemical performance of as-cast Pb-1 wt.% Sn and Pb-1 wt.% Sb alloys for lead-acid battery components

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, Wislei R.; Peixoto, Leandro C.; Garcia, Amauri [Department of Materials Engineering, University of Campinas - UNICAMP, PO Box 612, 13083-970 Campinas, SP (Brazil)

    2010-03-15

    A comparative experimental study of the electrochemical features of as-cast Pb-1 wt.% Sn and Pb-1 wt.% Sb alloys is carried out with a view to applications in the manufacture of lead-acid battery components. The as-cast samples are obtained using a water-cooled unidirectional solidification system. Pb-Sn and Pb-Sb alloy samples having similar coarse cell arrays are subjected to corrosion tests in order to assess the effect of Sn or Sb segregation in the cell boundary on the electrochemical performance. Electrochemical impedance spectroscopy (EIS) diagrams, potentiodynamic polarization curves and an equivalent circuit analysis are used to evaluate the electrochemical parameters in a 0.5 M H{sub 2}SO{sub 4} solution at 25 C. Both the experimental and simulated EIS parameters evidence different kinetics of corrosion. The Pb-1 wt.% Sn alloy is found to have a current density which is of about three times lower than that of the Pb-1 wt.% Sb alloy which indicates that dilute Pb-Sn alloys have higher potential for application as positive grid material in maintenance-free Pb-acid batteries. (author)

  12. A survey of the mechanical properties of uranium alloys U-5Mo-3Nb wt.% and U-3Mo-3Nb wt.%

    Energy Technology Data Exchange (ETDEWEB)

    Dupont, G.

    1969-04-15

    In a continuing program on the development of soft and ductile uranium alloys for armament applications, two compositions were studied. These gamma extruded uranium alloys were U-5Mo-3Nb wt.% and U-3Mo-3Nb wt.%. This study was carried out to determine the influence of tempering heat treatments associated with extrusion on the ductility of these uranium alloys. The mechanical properties of both alloys were measured in the extruded condition, in the extruded and annealed condition and in the quenched and tempered condition. A maximum elongation of 13.7% in tension with a low amount of work hardening was obtained for the U-3Mo-3Nb wt.% alloy after 1 1/2 hours anneal at 1200 deg F (650 deg C) followed by a rapid cooling in water at 70 deg F (21 deg C). A maximum elongation of 17.3% with a large amount of work hardening was obtained for alloy U-5Mo-3Nb wt.% after vacuum annealing, normalizing, gamma phase solubilizing at 1500 deg F (815 deg C) and quenching in water at 700 deg F (210 deg C). The maximum ductility achieved in these two alloys by our approaches is low compared with the ductility of Armco Iron employed for the same applications in the field of ballistics.

  13. Formation and growth of crystal defects in directionally solidified multicrystalline silicon for solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Ryningen, Birgit

    2008-07-01

    Included in this thesis are five publications and one report. The common theme is characterisation of directionally solidified multicrystalline silicon for solar cells. Material characterisation of solar cell silicon is naturally closely linked to both the casting process and to the solar cell processing: Many of the material properties are determined by the casting process, and the solar cell processing will to some extend determine which properties will influence the solar cell performance. Solar grade silicon (SoG-Si) made by metallurgical refining route and supplied by Elkem Solar was directionally solidified and subsequently characterised, and a simple solar cell process was applied. Except from some metallic co-precipitates in the top of the ingot, no abnormalities were found, and it is suggested that within the limits of the tests performed in this thesis, the casting and the solar cell processing, rather than the assumed higher impurity content, was the limiting factor. It is suggested in this thesis that the main quality problem in multicrystalline silicon wafers is the existence of dislocation clusters covering large wafer areas. The clusters will reduce the effect of gettering and even if gettering could be performed successfully, the clusters will still reduce the minority carrier mobility and hence the solar cell performance. It has further been pointed out that ingots solidified under seemingly equal conditions might have a pronounced difference in minority carrier lifetime. Ingots with low minority carrier lifetime have high dislocation densities. The ingots with the substantially higher lifetime seem all to be dominated by twins. It is also found a link between a higher undercooling and the ingots dominated by twins. It is suggested that the two types of ingots are subject to different nucleation and crystal growth mechanisms: For the ingots dominated by dislocations, which are over represented, the crystal growth is randomly nucleated at the

  14. Highlighting micrographic structures of uranium alloys containing 0.5 to 10 per cent wt molybdenum

    International Nuclear Information System (INIS)

    Laniesse, J.; Bouleau, M.

    1959-02-01

    The authors report a study which aimed at determining for different uranium molybdenum alloys and with respect to their molybdenum content a polishing method which allows a relatively simple grain examination in the as-cast condition, an as perfect as possible resolution of eutectic decompositions, and the appropriate conditions to highlight structures (beta-alpha and gamma-alpha martensite transformations, beta phase retention and decomposition, transient structures, eutectoid decomposition, and so on). Alloys differ by their molybdenum content: from 0.5 to 1 per cent wt, 1.5 to 3 per cent wt, 5 to 10 per cent wt

  15. Effect of Pre-Aging Conditions on Bake-Hardening Response of Al-0.4 wt%Mg-1.2 wt%Si-0.1 wt%Mn Alloy Sheets

    International Nuclear Information System (INIS)

    Lee, Kwang-jin; Woo, Kee-do

    2011-01-01

    Pre-aging heat treatment after solution heat treatment (SHT) of Al-0.4 wt%Mg-1.2 wt%Si-0.1 wt%Mn alloy sheets for auto-bodies was carried out to investigate the effect of pre-aging and its conditions on the bake-hardening response. Mechanical properties were evaluated by a tensile and Vickers hardness test. Microstructural observation was also performed using a transmission electron microscope (TEM). It was revealed that pre-aging treatments play a great role in the bake-hardening response. In addition, it was found that the sphere-shaped nanosized clusters that can directly transit to the needle-shaped β” phase during the paint-bake process, not being dissolved into the matrix, are formed at 343 K. The result, reveals that the dominant factor of the bake-hardening response is the pre-aging temperature rather than the pre-aging time.

  16. Interplay between temperature gradients field and C - E transformation in solidifying rolls

    Directory of Open Access Journals (Sweden)

    W. Wołczyński

    2009-07-01

    Full Text Available At first step of simulation a temperature field for solidifying cast steel and cast iron roll has been performed. The calculation does not take into account the convection in the liquid since convection has no influence on the proposed model for the localization of the C-E (columnar to equiaxed grains transformation. However, it allows to study the dynamics of temperature field temporal behavior in the middle of a mould. It is postulated that for the C-E transition a full accumulation of the heat in the mould has been observed (plateau at the T(t curve. The temporal range of plateau existence corresponds to the incubation time for the full equiaxed grains formation. At the second step of simulation temporal behavior of the temperature gradient field has been studied. Three ranges within temperature gradients field have been distinguished for the operating point situated at the middle of mould: a/ for the formation of columnar grains zone, ( and high temperature gradient 0>>T&0//>>∂∂−∂∂∂∂−∂∂>EttEtrTrT. T - temperature, r - roll radius. It is evident that the heat transfer across the mould decides on the temporal appearance of incubation during which the solidification is significantly arrested and competition between columnar and equiaxed growth occurs. Moreover solidification with positive temperature gradient transforms into solidification with negative temperature gradient (locally after the incubation. A simulation has been performed for the cast steel and cast iron rolls solidifying as in industry condition. Since the incubation divides the roll into to parts (first with columnar structure, second with equiaxed structure some experiments dealing with solidification have been made in laboratory scale. Finally, observations of the macrosegregation or microsegregation and phase or structure appearance in the cast iron ingot / roll (made in laboratory has also been done in order to confront them with theoretical predictions

  17. Preparation and investigation of Al–4 wt % B4C nanocomposite ...

    Indian Academy of Sciences (India)

    cal behaviour including light weight, electrical and thermal conductivity (Boey et ... cle sizes, density, geometries, flow or the development of an electrical charge ... 2. Experimental. Argon gas atomized Al–2 wt % Cu powders with a mean size.

  18. SUSY WT identity in a lattice formulation of 2D N=(2,2) SYM

    International Nuclear Information System (INIS)

    Kadoh, Daisuke; Suzuki, Hiroshi

    2010-01-01

    We address some issues relating to a supersymmetric (SUSY) Ward-Takahashi (WT) identity in Sugino's lattice formulation of two-dimensional (2D) N=(2,2)SU(k) supersymmetric Yang-Mills theory (SYM). A perturbative argument shows that the SUSY WT identity in the continuum theory is reproduced in the continuum limit without any operator renormalization/mixing and tuning of lattice parameters. As application of the lattice SUSY WT identity, we show that a prescription for the Hamiltonian density in this lattice formulation, proposed by Kanamori, Sugino and Suzuki, is justified also from a perspective of an operator algebra among correctly-normalized supercurrents. We explicitly confirm the SUSY WT identity in the continuum limit to the first nontrivial order in a semi-perturbative expansion.

  19. Characterization and property evaluation of U–15 wt%Pu alloy for fast reactor

    International Nuclear Information System (INIS)

    Kaity, Santu; Banerjee, Joydipta; Ravi, K.; Keswani, R.; Kutty, T.R.G.; Kumar, Arun; Prasad, G.J.

    2013-01-01

    The characterization and high temperature behaviour of U–15 wt%Pu alloy has been investigated in this study for the first time. U–15 wt%Pu alloy sample for this study was prepared by following melting and casting route. Microstructural characterization of the alloy was carried out by XRD and optical microscopy. The thermophysical properties like phase transition temperatures, coefficient of thermal expansion and hot hardness of the above alloy were determined. Eutectic temperature between T91 and U–15 wt%Pu was established. Apart from that, the fuel–cladding chemical compatibility of U–15 wt%Pu alloy with T91 grade steel was studied by diffusion couple experiment

  20. Experimental determination of the H2O + 15 wt% NaCl and H2O + 25 wt% NaCl liquidi to 1.4 GPa

    Science.gov (United States)

    Valenti, P.; Schmidt, C.

    2009-12-01

    The binary H2O+NaCl is one of the most important model systems for chloridic fluids in many geologic environments such as the Earth’s crust, upper mantle, and subducting slabs, and is also applicable to extraterrestrial icy planetary bodies (e.g., Manning 2004, Zolensky et al., 1999). The knowledge on phase equilibria and PVTx properties of this system is still fragmentary at high pressures, e.g., very little has been reported on liquidi at compositions Daniel 2008). In this study, we investigated the liquidus of 15 and 25 wt% NaCl solutions at pressures up to 1.4 GPa. The experiments were performed using a hydrothermal diamond-anvil cell (Bassett et al. 1993) modified for Raman spectroscopy and accurate temperature measurements. A quartz chip, halite, and water were loaded into the sample chamber, which also contained a small trapped air bubble (10 vol%) when it was sealed. The actual salinity was then determined from measurement of the vapor-saturated liquidus temperature. The sample chamber was then compressed until the bubble disappeared. After freezing, phase transitions occurring with increasing temperature were observed optically, and the pressure was determined from the frequency shift of the 464 cm-1 Raman line of quartz (Schmidt and Ziemann 2000). The sample chamber was then compressed further, and the experiment was repeated at various bulk densities until a pressure of ~1.4 GPa was attained. At some conditions, Raman spectra were acquired for identification of the phase assemblage. The solution always crystallized to a single phase upon cooling above ~0.15 GPa at 25 wt% NaCl and above ~1 GPa at 15 wt% NaCl. Raman spectra in the OH stretching region indicate that this phase contains or is a NaCl hydrate other than hydrohalite, probably in solid solution with ice. Melting of this phase produced liquid and hydrohalite and/or ice VI. Ice VI was the last solid that dissolved upon heating, between 1100 MPa, 3 °C and 1370 MPa, 17 °C for 15 wt% NaCl and at

  1. Microstructural evolution of a uranium-10 wt.% molybdenum alloy for nuclear reactor fuels

    International Nuclear Information System (INIS)

    Clarke, A.J.; Clarke, K.D.; McCabe, R.J.; Necker, C.T.; Papin, P.A.; Field, R.D.; Kelly, A.M.; Tucker, T.J.; Forsyth, R.T.; Dickerson, P.O.; Foley, J.C.; Swenson, H.; Aikin, R.M.; Dombrowski, D.E.

    2015-01-01

    Low-enriched uranium-10 wt.% molybdenum (LEU-10wt.%Mo) is of interest for the fabrication of monolithic fuels to replace highly-enriched uranium (HEU) dispersion fuels in high performance research and test reactors around the world. In this work, depleted uranium-10 wt.%Mo (DU-10wt.%Mo) is used to simulate the solidification and microstructural evolution of LEU-10wt.%Mo. Electron backscatter diffraction (EBSD) and complementary electron probe microanalysis (EPMA) reveal significant microsegregation present in the metastable γ-phase after solidification. Homogenization is performed at 800 and 1000 °C for times ranging from 1 to 32 h to explore the time–temperature combinations that will reduce the extent of microsegregation, as regions of higher and lower Mo content may influence local mechanical properties and provide preferred regions for γ-phase decomposition. We show for the first time that EBSD can be used to qualitatively assess microstructural evolution in DU-10wt.%Mo after homogenization treatments. Complementary EPMA is used to quantitatively confirm this finding. Homogenization at 1000 °C for 2–4 h may the regions that contain 8 wt.% Mo or lower, whereas homogenization at 1000 °C for longer than 8 h effectively saturates Mo chemical homogeneity, but results in substantial grain growth. The appropriate homogenization time will depend upon additional microstructural considerations, such as grain growth and intended subsequent processing. Higher carbon LEU-10wt.%Mo generally contains more inclusions within the grains and at grain boundaries after solidification. The effect of these inclusions on microstructural evolution (e.g. grain growth) during homogenization and as potential γ-phase decomposition nucleation sites is unclear, but likely requires additional study.

  2. Faults detection approach using PCA and SOM algorithm in PMSG-WT system

    Directory of Open Access Journals (Sweden)

    Mohamed Lamine FADDA

    2016-07-01

    Full Text Available In this paper, a new approach for faults detection in observable data system wind turbine - permanent magnet synchronous generator (WT-PMSG, the studying objective, illustrate the combination (SOM-PCA to build Multi-local-PCA models faults detection in system (WT-PMSG, the performance of the method suggested to faults detection in system data, finding good results in simulation experiment.

  3. The transformation behaviour of the beta phase in Zr-2.5 wt% Nb pressure tubes

    International Nuclear Information System (INIS)

    Griffiths, M.; Winegar, J.E.

    1994-12-01

    A temperature-time-transformation (TTT) diagram has been developed for the β-phase in Zr-2.5 wt% Nb pressure tubes. The results show that the morphology and/or physical state of the β-phase in pressure tubes has a significant effect on the transformation behaviour compared with a bulk Zr-19 wt%Nb alloy. (author). 14 refs., 1 tab., 15 figs

  4. Study on the Mechanical Properties and Corrosion Behaviors of Fe-(20, 45) wt%Gd Intermetallics

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Bo Kyeong; Baik, Youl; Choi, Yong [Dankook University, Chungnam (Korea, Republic of); Moon, Byung Moon [Korea Institute of Industrial Technology, Incheon (Korea, Republic of)

    2017-02-15

    Fe-(20, 45 wt%) Gd intermetallics were vacuum arc melted as the mother alloy of a neutron shielding and absorbing material. The structure of the cast Fe-20 wt%Gd intermetallics had primary dendrites with a short width of about 2 μm, which became coarse with increasing Gd content. The final compositions of the Fe-20 wt%Gd and Fe-45 wt%Gd intermetallics determined by Rietveld refinement were mainly Fe{sub 3}Gd with 26.6 at%Fe{sub 2}Gd, and Fe{sub 3}Gd with various intermetallics like 13.9 at%Fe{sub 2}Gd, 7.3 at%Fe{sub 9}Gd and 3.9 at%Fe{sub 17}Gd{sub 2}, respectively. The micro-hardnesses, yield strength, ultimate compressive strength and elongation of the Fe-20 wt%Gd intermetallics were 629±12 Hv, 753 MPa, 785 MPa and 4%, respectively, and those of the Fe-45 wt%Gd intermetallics were 741±13 Hv, 772 MPa, 823 MPa and 3%. Passivity was not present in artificial sea water at room temperature. The corrosion potentials and the corrosion rates of the Fe-20 wt%Gd and Fe-45 wt%Gd intermetallics were –624 mV{sub SHE}, 2.771 mA/cm{sup 2} , and –804 mV{sub SHE}, 3.397 mA/cm{sup 2} , respectively. The corroded surface of the Fe-Gd intermetallics contained corrosion products like gadolinium with iron, which detached to leave a trail of pits.

  5. Microstructural evolution of a uranium-10 wt.% molybdenum alloy for nuclear reactor fuels

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, A.J., E-mail: aclarke@lanl.gov; Clarke, K.D.; McCabe, R.J.; Necker, C.T.; Papin, P.A.; Field, R.D.; Kelly, A.M.; Tucker, T.J.; Forsyth, R.T.; Dickerson, P.O.; Foley, J.C.; Swenson, H.; Aikin, R.M.; Dombrowski, D.E.

    2015-10-15

    Low-enriched uranium-10 wt.% molybdenum (LEU-10wt.%Mo) is of interest for the fabrication of monolithic fuels to replace highly-enriched uranium (HEU) dispersion fuels in high performance research and test reactors around the world. In this work, depleted uranium-10 wt.%Mo (DU-10wt.%Mo) is used to simulate the solidification and microstructural evolution of LEU-10wt.%Mo. Electron backscatter diffraction (EBSD) and complementary electron probe microanalysis (EPMA) reveal significant microsegregation present in the metastable γ-phase after solidification. Homogenization is performed at 800 and 1000 °C for times ranging from 1 to 32 h to explore the time–temperature combinations that will reduce the extent of microsegregation, as regions of higher and lower Mo content may influence local mechanical properties and provide preferred regions for γ-phase decomposition. We show for the first time that EBSD can be used to qualitatively assess microstructural evolution in DU-10wt.%Mo after homogenization treatments. Complementary EPMA is used to quantitatively confirm this finding. Homogenization at 1000 °C for 2–4 h may the regions that contain 8 wt.% Mo or lower, whereas homogenization at 1000 °C for longer than 8 h effectively saturates Mo chemical homogeneity, but results in substantial grain growth. The appropriate homogenization time will depend upon additional microstructural considerations, such as grain growth and intended subsequent processing. Higher carbon LEU-10wt.%Mo generally contains more inclusions within the grains and at grain boundaries after solidification. The effect of these inclusions on microstructural evolution (e.g. grain growth) during homogenization and as potential γ-phase decomposition nucleation sites is unclear, but likely requires additional study.

  6. Properties of rapidly solidified Fe-Cr-Al ribbons for the use as automotive exhaust gas catalyst substrates

    International Nuclear Information System (INIS)

    Emmerich, K.

    1993-01-01

    Metallic honeycomb structures are used as catalyst substrates in automotive exhaust gas systems. This application requires an outstanding corrosion resistance at elevated temperatures of the substrate material. Technical improvements can be achieved by the use of rapid solidification technology for the production of the Fe-Cr-Al ribbons since the Al content can be substantially increased from about 5% Al in the conventionally rolled material to about 12% Al in the rapid solidified ribbon. As a result the lifetime of the ribbon in a higher-temperature corrosion environment is drastically increased. In addition the scale/metal adherance is improved. The impediment of recrystallization in the rapidly solidified ribbons prevents an embrittlement even in carbonizing atmospheres. (orig.)

  7. Evaluation of the performance of solidified commercial low-level wastes in an arid climate

    International Nuclear Information System (INIS)

    Graham, M.J.; Walter, M.B.

    1984-01-01

    Shallow land burial is being used as a disposal method for commercial low-level waste at waste disposal sites in arid (Hanford, Washington) and humid (Barnwell, South Carolina) climatic regions. A field lysimeter facility has been established at Hanford in which to conduct waste-form leaching tests. The primary objective of this research is to determine typical source terms generated by commercial solidified low-level wastes. The field lysimeter facility consists of 10, 3 M deep by 1.8 M diameter, closed-bottomed lysimeters around a central 4 M deep by 4 M diameter instrument caisson. Commercial cement and dow polymer waste samples were removed from 210 L drums and placed in the 1.8 M diameter lysimeters. Two bitumen samples are planned to be emplaced in the facility this year. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste forms. Suction candles (ceramic cups) placed around the waste will be used to periodically collect soil water samples for chemical analysis. Meteorological data, moisture content, and soil temperature are being automatically monitored at the facility. Characterization of the soils and waste forms have been partially completed. These data consist of moisture release characteristics, particle size distribution, concentrations and distributions of radionuclides in the waste streams, and concentrations of hydrophilic organic species in one of the waste streams

  8. Disposal and long-term storage in geological formations of solidified radioactive wastes

    International Nuclear Information System (INIS)

    Shischits, I.

    1996-01-01

    The special depository near Krasnoyarsk contains temporarily about 1,100 tons of spent nuclear fuel (SNF) from WWR- should be solidified and for the most part buried in geological formations. Solid wastes and SNF from RBMK reactors are assumed to be buried as well. For this purpose special technologies and underground constructions are required. They are to be created in the geological plots within the territory of Russian Federation and adjacent areas of CIS, meeting the developed list of requirements. The burial structures will vary greatly depending on the geological formation, the amount of wastes and their isotope composition. The well-known constructions such as deep wells, shafts, mines and cavities can be mentioned. There is a need to design constructions, which have no analog in the world practice. In the course of the Project fulfillment the following work will be conducted: -theoretical work followed by code creation for mathematical simulation of processes; - modelling on the base of prototypes made from equivalent materials with the help of simulators; - bench study; - experiments in real conditions; - examination of massif properties in particular plots using achievements of geophysics, including gamma-gamma density detectors and geo locators. Finally, ecological-economical model will be given for designing burial sites

  9. Evaluation of the performance of solidified commercial low-level wastes in an arid climate

    International Nuclear Information System (INIS)

    Graham, M.J.; Walter, M.B.

    1984-09-01

    Shallow land burial is being used as a disposal method for commercial low-level waste at waste disposal sites in arid (Hanford site near Richland, Washington) and humid (Barnwell, South Carolina) climatic regions. A field lysimeter facility has been established at the Hanford site in which to conduct waste-form leaching tests. The primary objective of this research is to determine typical source terms generated by commercial solidified low-level wastes. The field lysimeter facility consists of ten 3-m-deep by 1.8-m-diameter, closed-bottom lysimeters around a central instrument caisson, 4 m in diameter. Commercial cement and vinyl ester-styrene waste samples were removed from 210-L drums and placed in the 1.8-m-diameter lysimeters. Two bitumen samples are planned to be emplaced in the facility in 1984. The central caisson provides access to the instrumentation in the individual lysimeters and allows selective sampling of the soil and waste forms. Suction candles (ceramic cups) placed around the waste will be used to periodically collect soil water samples for chemical analysis. Meteorological data, moisture content, and soil temperature are automatically monitored at the facility. Characterization of the soils and waste forms have been partially completed. These data consist of moisture release characteristics, particle size distribution, concentrations and distributions of radionuclides in the waste forms, concentrations of radionuclides in the waste streams, and concentrations of hydrophilic organic species in one of the waste steams. 8 references, 3 figures, 5 tables

  10. On oscillatory microstructure during cellular growth of directionally solidified Sn–36at.%Ni peritectic alloy

    Science.gov (United States)

    Peng, Peng; Li, Xinzhong; Li, Jiangong; Su, Yanqing; Guo, Jingjie

    2016-01-01

    An oscillatory microstructure has been observed during deep-cellular growth of directionally solidified Sn–36at.%Ni hyperperitectic alloy containing intermetallic compounds with narrow solubility range. This oscillatory microstructure with a dimension of tens of micrometers has been observed for the first time. The morphology of this wave-like oscillatory structure is similar to secondary dendrite arms, and can be observed only in some local positions of the sample. Through analysis such as successive sectioning of the sample, it can be concluded that this oscillatory microstructure is caused by oscillatory convection of the mushy zone during solidification. And the influence of convection on this oscillatory microstructure was characterized through comparison between experimental and calculations results on the wavelength. Besides, the change in morphology of this oscillatory microstructure has been proved to be caused by peritectic transformation during solidification. Furthermore, the melt concentration increases continuously during solidification of intermetallic compounds with narrow solubility range, which helps formation of this oscillatory microstructure. PMID:27066761

  11. Synthesis of laser beam rapidly solidified novel surfaces on D2 tool steel

    International Nuclear Information System (INIS)

    Ahmed, B.A.; Rizwan, K.F.; Minhas, J.A.; Waheed-ul-Haq, S.; Shahid, M.

    2011-01-01

    Surface layer of D2 tool steel was subjected to laser surface melting using continuous wave 2.5 kW CO/sub 2/ laser in point source melting mode. The processing parameters were varied to achieve a uniform depth of around 2 mm. Microstructural study revealed epitaxial growth of fine dendritic structure with secondary dendrite arm spacing in the range of 20-25 mu m. The phases in the parent annealed sample were BCC ferrite and chromium rich M7C3 carbide. The major phase after laser treatment was austenite and M7C3. The average hardness of annealed sample was 195 HV which increased to 410 HV after laser melting. Corrosion studies in 2% HCl solution exhibited a drastic improvement in corrosion resistance in laser treated samples. Improvement in properties is attributed to the refinement and uniformity of microstructure in the rapidly solidified surface. The case of a moving heat source was subjected to computer aided simulation to predict the melt depth at different processing conditions in point source melting mode. The calculated depths using the model, in ABAQUS software was found in good agreement with the experimental data. (author)

  12. Preparation and Stability of Inorganic Solidified Foam for Preventing Coal Fires

    Directory of Open Access Journals (Sweden)

    Botao Qin

    2014-01-01

    Full Text Available Inorganic solidified foam (ISF is a novel material for preventing coal fires. This paper presents the preparation process and working principle of main installations. Besides, aqueous foam with expansion ratio of 28 and 30 min drainage rate of 13% was prepared. Stability of foam fluid was studied in terms of stability coefficient, by varying water-slurry ratio, fly ash replacement ratio of cement, and aqueous foam volume alternatively. Light microscope was utilized to analyze the dynamic change of bubble wall of foam fluid and stability principle was proposed. In order to further enhance the stability of ISF, different dosage of calcium fluoroaluminate was added to ISF specimens whose stability coefficient was tested and change of hydration products was detected by scanning electron microscope (SEM. The outcomes indicated that calcium fluoroaluminate could enhance the stability coefficient of ISF and compact hydration products formed in cell wall of ISF; naturally, the stability principle of ISF was proved right. Based on above-mentioned experimental contents, ISF with stability coefficient of 95% and foam expansion ratio of 5 was prepared, which could sufficiently satisfy field process requirements on plugging air leakage and thermal insulation.

  13. High temperature low cycle fatigue behavior of a directionally solidified Ni-base superalloy DZ951

    International Nuclear Information System (INIS)

    Chu Zhaokuang; Yu Jinjiang; Sun Xiaofeng; Guan Hengrong; Hu Zhuangqi

    2008-01-01

    Total strain-controlled low cycle fatigue (LCF) tests were performed at a temperature range from 700 to 900 deg. C in ambient air condition on a directionally solidified Ni-base superalloy DZ951. The fatigue life of DZ951 alloy does not monotonously decrease with increasing temperature, but exhibits a strong dependence on the total strain range. The dislocation characteristics and failed surface observation were evaluated through transmission electron microscopy and scanning electron microscopy. The alloy exhibits cyclic hardening, softening or cyclic stability as a whole, which is dependent on the testing temperature and total strain range. At 700 deg. C, the cyclic plastic deformation process is the main cause of fatigue failure. At 900 deg. C, the failure mostly results from combined fatigue and creep damage under total strain range from 0.6 to 1.2% and the reduction in fatigue life can be taken as the cause of oxidation, creep and cyclic plastic deformation under total strain range of 0.5%

  14. Comparison of ice particle morphology crushed from ice chunk and directly solidified from droplet

    Energy Technology Data Exchange (ETDEWEB)

    Yang, J.H.; Yoon, Y.S.; Bang, S.Y. [Dongguk Univ., Pil-dong, Chung-gu, Seoul (Korea, Republic of). Dept. of Mechanical Engineering

    2008-07-01

    In order to investigate the transition kinetics of ice to hydrate and to produce standard specimens of hydrate pellet from prepared hydrate powders, fine ice beads with uniform diameters must be fabricated. This paper discussed the construction of several experimental setups for the fabrication of fine ice particle generation. The ultrasonic nozzle was used to produce fine mist which solidified near the free surface of liquid nitrogen bath. The shape and population distribution of ice bead diameters was analyzed. The study also compared ice particles produced by crushing. The surface morphology of ice particles produced with a ball mill was also examined. Experimental results were obtained for an ice shaver, ball mill, bowl for grinding medicine, and ultrasonic nozzle. It was concluded that the information generated from the study was useful in estimating the macroscopic flow characteristics such as permeability of bulk powder and in determining mean effective diameter of irregular shaped particles. Future work was also noted as being underway with different experiments for other cases with different operating conditions. 5 refs., 5 figs.

  15. Electron microscopy investigations of rapidly solidified Fe-Zr-B-Cu alloys

    International Nuclear Information System (INIS)

    Majumdar, B.; Arvindha Babu, D.; Akhtar, D.

    2010-01-01

    Rapidly solidified Fe-based nanocrystalline soft magnetic materials possess a unique combination of properties i,e high permeability, saturation and Curie temperature and very low coercivity which are otherwise not attainable in conventional soft magnetic materials. The alloys are processed by producing amorphous phase through melt spinning route followed by a partial devitrification for incorporation of nanocrystalline phase in the amorphous matrix. In this paper, detailed electron microscopic investigations of melt spun Fe-Zr-B-Cu alloys are presented. Melt spun ribbons of Fe 99-x-y Zr x BCu 1 alloys with x+y = 11 and x+y = 13 were prepared under different wheel speed conditions and then vacuum annealed for 1 h at different temperatures. The microstructure changes from completely amorphous to a cellular/dendritic bcc solid solution coexisting with the amorphous phase at intercellular/dendritic regions when Zr/B ratio or the process parameters are varied. Annealing leads to the precipitation of nanocrystalline bcc-Fe phase from both amorphous phase and already existing bcc solid solution. (author)

  16. Particle Engulfment and Pushing by Solidifying Interfaces. Pt. 2; Micro-Gravity Experiments and Theoretical Analysis

    Science.gov (United States)

    Stefanescu, Doru M.; Juretzko, Frank R.; Dhindaw, Brij K.; Catalina, Adrian; Sen, Subhayu; Curreri, Peter A.

    1998-01-01

    Results of the directional solidification experiments on Particle Engulfment and Pushing by Solidifying Interfaces (PEP) conducted on the space shuttle Columbia during the Life and Microgravity Science Mission are reported. Two pure aluminum (99.999%) 9 mm cylindrical rods, loaded with about 2 vol.% 500 micrometers diameter zirconia particles were melted and resolidified in the microgravity (microg) environment of the shuttle. One sample was processed at step-wise increased solidification velocity, while the other at step-wise decreased velocity. It was found that a pushing-to-engulfment transition (PET) occurred in the velocity range of 0.5 to 1 micrometers. This is smaller than the ground PET velocity of 1.9 to 2.4 micrometers. This demonstrates that natural convection increases the critical velocity. A previously proposed analytical model for PEP was further developed. A major effort to identify and produce data for the surface energy of various interfaces required for calculation was undertaken. The predicted critical velocity for PET was of 0.775 micrometers/s.

  17. Evaluating Local Primary Dendrite Arm Spacing Characterization Techniques Using Synthetic Directionally Solidified Dendritic Microstructures

    Science.gov (United States)

    Tschopp, Mark A.; Miller, Jonathan D.; Oppedal, Andrew L.; Solanki, Kiran N.

    2015-10-01

    Microstructure characterization continues to play an important bridge to understanding why particular processing routes or parameters affect the properties of materials. This statement certainly holds true in the case of directionally solidified dendritic microstructures, where characterizing the primary dendrite arm spacing is vital to developing the process-structure-property relationships that can lead to the design and optimization of processing routes for defined properties. In this work, four series of simulations were used to examine the capability of a few Voronoi-based techniques to capture local microstructure statistics (primary dendrite arm spacing and coordination number) in controlled (synthetically generated) microstructures. These simulations used both cubic and hexagonal microstructures with varying degrees of disorder (noise) to study the effects of length scale, base microstructure, microstructure variability, and technique parameters on the local PDAS distribution, local coordination number distribution, bulk PDAS, and bulk coordination number. The Voronoi tesselation technique with a polygon-side-length criterion correctly characterized the known synthetic microstructures. By systematically studying the different techniques for quantifying local primary dendrite arm spacings, we have evaluated their capability to capture this important microstructure feature in different dendritic microstructures, which can be an important step for experimentally correlating with both processing and properties in single crystal nickel-based superalloys.

  18. The development of basic glass formulations for solidifying HLW from nuclear fuel reprocessing plant

    International Nuclear Information System (INIS)

    Jiang Yaozhong; Tang Baolong; Zhang Baoshan; Zhou Hui

    1995-01-01

    Basic glass formulations 90U/19, 90U/20, 90Nd/7 and 90Nd/10 applied in electric melting process are developed by using the mathematical model of the viscosity and electric resistance of waste glass. The yellow phase does not occur for basic glass formulations 90U/19 and 90U/20 solidifying HLW from nuclear fuel reprocessing plant when the waste loading is 20%. Under the waste loading is 16%, the process and product properties of glass 90U/19 and 90U/20 come up to or surpass the properties of the same kind of foreign waste glasses, and other properties are about the same to them of foreign waste glasses. The process and product properties of basic glass formulations 90Nd/7 and 90Nd/10 used for the solidification of 'U replaced by Nd' liquid waste are almost similar to them of 90U/19 and 90U/20. These properties fairly meet the requirements of 'joint test' (performed at KfK-INE, Germany). Among these formulations, 90Nd/7 is applied in cold engineering scale electric melting test performed at KfK-INE in Germany. The main process properties of cold test is similar to laboratory results

  19. Review of metal-matrix encapsulation of solidified radioactive high-level waste

    International Nuclear Information System (INIS)

    Jardine, L.J.; Steindler, M.J.

    1978-05-01

    Literature describing previous and current work on the encapsulation of solidified high-level waste forms in a metal matrix was reviewed. Encapsulation of either stabilized calcine pellets or glass beads in alloys by casting techniques was concluded to be the most developed and direct approach to fabricating solid metal-matrix waste forms. Further characterizations of the physical and chemical properties of metal-matrix waste forms are still needed to assess the net attributes of metal-encapsulation alternatives. Steady-state heat transfer properties of waste canisters in air and water environments were calculated for four reference waste forms: (1) calcine, (2) glass monoliths, (3) metal-encapsulated calcine, and (4) metal-encapsulated glass beads. A set of criteria for the maximum allowable canister centerline and surface temperatures and heat generation rates per canister at the time of shipment to a Federal repository was assumed, and comparisons were made between canisters of these reference waste forms of the shortest time after reactor discharge that canisters could be filled and the subsequent ''interim'' storage times prior to shipment to a Federal repository for various canister diameters and waste ages. A reference conceptual flowsheet based on existing or developing technology for encapsulation of stabilized calcine pellets is discussed. Conclusions and recommendations are presented

  20. Leaching behaviour and mechanical properties of copper flotation waste in stabilized/solidified products.

    Science.gov (United States)

    Mesci, Başak; Coruh, Semra; Ergun, Osman Nuri

    2009-02-01

    This research describes the investigation of a cement-based solidification/stabilization process for the safe disposal of copper flotation waste and the effect on cement properties of the addition of copper flotation waste (CW) and clinoptilolite (C). In addition to the reference mixture, 17 different mixtures were prepared using different proportions of CW and C. Physical properties such as setting time, specific surface area and compressive strength were determined and compared to a reference mixture and Turkish standards (TS). Different mixtures with the copper flotation waste portion ranging from 2.5 to 12.5% by weight of the mixture were tested for copper leachability. The results show that as cement replacement materials especially clinoptilolite had clear effects on the mechanical properties. Substitution of 5% copper flotation waste for Portland cement gave a similar strength performance to the reference mixture. Higher copper flotation waste addition such as 12.5% replacement yielded lower strength values. As a result, copper flotation waste and clinoptilolite can be used as cementitious materials, and copper flotation waste also can be safely stabilized/solidified in a cement-based solidification/stabilization system.

  1. Measurements of Mercury Released From Solidified/Stabilized Waste Forms-FY2002

    International Nuclear Information System (INIS)

    Mattus, C.H.

    2003-01-01

    This report covers work performed during FY 2002 in support of treatment demonstrations conducted for the U.S. Department of Energy (DOE) Mixed Waste Focus Area (MWFA) Mercury Working Group. To comply with the requirements of the Resource Conservation and Recovery Act, as implemented by the U.S. Environmental Protection Agency (EPA), DOE must use one of the following procedures for mixed low-level radioactive wastes containing mercury at levels above 260 ppm: a retorting/roasting treatment or (if the wastes also contain organics) an incineration treatment. The recovered radioactively contaminated mercury must then be treated by an amalgamation process prior to disposal. The DOE MWFA Mercury Working Group is working with EPA to determine whether some alternative processes could be used to treat these types of waste directly, thereby avoiding a costly recovery step for DOE. In previous years, demonstrations were performed in which commercial vendors applied their technologies for the treatment of radiologically contaminated elemental mercury as well as radiologically contaminated and mercury-contaminated waste soils from Brookhaven National Laboratory. The test results for mercury release in the headspace were reported in two reports, ''Measurements of Mercury Released from Amalgams and Sulfide Compounds'' (ORNL/TM-13728) and ''Measurements of Mercury Released from Solidified/Stabilized Waste Forms'' (ORNL/TM-2001/17). The current work did not use a real waste; a surrogate sludge had been prepared and used in the testing in an effort to understand the consequences of mercury speciation on mercury release

  2. Strength, leachability and microstructure characteristics of cement-based solidified plating sludge

    International Nuclear Information System (INIS)

    Asavapisit, Suwimol; Naksrichum, Siripat; Harnwajanawong, Naraporn

    2005-01-01

    The solidification of the stabilized zinc-cyanide plating sludge was carried out using ordinary Portland cement (OPC) and pulverized fuel ash (PFA) as solidification binders. The plating sludge were used at the level of 0%, 10%, 20% and 30% dry weight, and PFA was used to replace OPC at 0%, 10%, 20% and 30% dry weight, respectively. Experimental results showed that a significant reduction in strength was observed when the plating sludge was added to both the OPC and OPC/PFA binders, but the negative effect was minimized when PFA was used as part substitute for OPC. SEM observation reveals that the deposition of the plating sludge on the surface of the clinkers and PFA could be the cause for hydration retardation. In addition, calcium zinc hydroxide hydrate complex and the unreacted di- and tricalcium silicates were the major phases in X-ray diffraction (XRD) patterns of the solidified plating waste hydrated for 28 days, although the retardation effect on hydration reactions but Cr concentration in toxicity characteristic leaching procedure (TCLP) leachates was lower than the U.S. EPA regulatory limit

  3. Testing and evaluation of solidified high-level waste forms. Joint annual progress report 1983

    International Nuclear Information System (INIS)

    Malow, G.

    1985-01-01

    A second joint programme of the European Atomic Community was started in 1981 under the indirect action programme (1980-84), Action No 5 'Testing and evaluation of the properties of various potential materials for immobilizing high activity waste'. The overall objective of the research is to test various European potential solidified high-level radioactive waste forms so as to predict their behaviour after disposal. The most important aspect is to produce data to calculate the activity release from the waste products under the attack of various aqueous solutions. The experiments were partly performed under waste repository relevant conditions and partly under simplified conditions for investigating basic activity release mechanisms. The topics of the programme were: (i) studies of basic leaching mechanisms; (ii) studies of hydrothermal leaching and surface attack of waste glasses; (iii) leach test carried out in contact with granite at low water flow rates; (iv) static leach tests with specimen surrounded by canister and backfill materials; (v) specific isotope leach tests in slowly flowing water; (vi) leach test of actinide spiked samples; (vii) leach tests of highly radioactive samples; (viii) leach tests of alpha radiation stability; (ix) studies of mechanical stability; (x) studies of mineral phases as model compounds and phase relations

  4. Decomposition for the analysis of radionuclides in solidified cement radioactive waste

    International Nuclear Information System (INIS)

    Lee, Jeong Jin; Pyo, Hyung Yeal; Jee, Kwang Yung; Jeon, Jong Seon

    2004-01-01

    Spent ion exchange resins make solid radioactive wastes when mixed with cement as solidifying material that was widely used in securing human environment from radionuclides for at least hundreds years. The cumulative increase of low and medium level radioactive wastes results in capacity problem of temporary storage in some NPPs (Nuclear Power Plants) of Korea around 2008. Radioactive wastes are scheduled to be disposed in a permanent disposal facility in accordance with the Korean Radioactive Wastes Management Program. It is mandatory to identify kinds and concentration of radionuclides immobilized for transporting them from temporary storage in NPPs to disposal facility. Accordingly, the effective sample decomposition prior to radiochemical separation is prerequisite to obtain the analytical data about radionuclides in cement waste forms. The closed-vessel microwave digestion technology among several sample preparation methods is taken into account to decompose cement waste forms. In this study, SRM 1880a (Portland cement) which is known for its certified values was used to optimize decomposition condition of cement waste forms containing nonradioactive ion exchange resins from NPP. With such variables as reagents, time, and power, the variation of the transparency and the color of the solution after closed-vessel microwave digestion can be examine. SRM 1880a is decomposed by suggested digestion procedure and the recoveries of constituents were investigated by ICP-AES and AAS

  5. Giant Enhancement of Magnetostrictive Response in Directionally-Solidified Fe83Ga17Erx Compounds

    Directory of Open Access Journals (Sweden)

    Radhika Barua

    2018-06-01

    Full Text Available We report, for the first time, correlations between crystal structure, microstructure and magnetofunctional response in directionally solidified [110]-textured Fe83Ga17Erx (0 < x < 1.2 alloys. The morphology of the doped samples consists of columnar grains, mainly composed of a matrix phase and precipitates of a secondary phase deposited along the grain boundary region. An enhancement of more than ~275% from ~45 to 170 ppm is observed in the saturation magnetostriction value (λs of Fe83Ga17Erx alloys with the introduction of small amounts of Er. Moreover, it was noted that the low field derivative of magnetostriction with respect to an applied magnetic field (i.e., dλs/dHapp for Happ up to 1000 Oe increases by ~230% with Er doping (dλs/dHapp,FeGa= 0.045 ppm/Oe; dλs/dHapp,FeGaEr= 0.15 ppm/Oe. The enhanced magnetostrictive response of the Fe83Ga17Erx alloys is ascribed to an amalgamation of microstructural and electronic factors, namely: (i improved grain orientation and local strain effects due to deposition of Er in the intergranular region; and (ii strong local magnetocrystalline anisotropy, due to the highly anisotropic localized nature of the 4f electronic charge distribution of the Er atom. Overall, this work provides guidelines for further improving galfenol-based materials systems for diverse applications in the power and energy sector.

  6. Short-term thermal response of rapidly solidified Type 304 stainless steel containing helium

    International Nuclear Information System (INIS)

    Clark, D.E.

    1988-06-01

    Type 304 stainless steel was heat treated for short times near its melting point in order to determine its microstructural response to thermal cycles typical of the near heat-affected zones of welding processes. The material was rapidly solidified as a powder by centrifugal atomization in a helium environment and consolidated by hot extrusion. Along with the ingot metallurgy material used for canning the powder prior to hot extrusion, it was heat treated using a Gleeble at temperatures of 1200 and 1300 degree C for times ranging from <1 to 1000 s, and the samples were examined for microstructure and the existence of porosity due to entrapped helium. At higher test temperatures and longer treatment times, the material developed extensive porosity, which was stabilized by the presence of helium and which may also have a role in anchoring grain boundaries and inhibiting grain growth. The powder material. At lower test temperatures and shorter treatment times, grain growth in the γ phase appeared to be restricted in the powder material, possible by the presence of helium. An intermediate temperatures and times, a γ-δ duplex microstructure also restricted grain growth again occurred in the δ microstructure. 9 refs., 14 figs., 3 tabs

  7. Pore structure and mechanical properties of directionally solidified porous aluminum alloys

    Directory of Open Access Journals (Sweden)

    Komissarchuk Olga

    2014-01-01

    Full Text Available Porous aluminum alloys produced by the metal-gas eutectic method or GASAR process need to be performed under a certain pressure of hydrogen, and to carry over melt to a tailor-made apparatus that ensures directional solidification. Hydrogen is driven out of the melt, and then the quasi-cylindrical pores normal to the solidification front are usually formed. In the research, the effects of processing parameters (saturation pressure, solidification pressure, temperature, and holding time on the pore structure and porosity of porous aluminum alloys were analyzed. The mechanical properties of Al-Mg alloys were studied by the compressive tests, and the advantages of the porous structure were indicated. By using the GASAR method, pure aluminum, Al-3wt.%Mg, Al-6wt.%Mg and Al-35wt.%Mg alloys with oriented pores have been successfully produced under processing conditions of varying gas pressure, and the relationship between the final pore structure and the solidification pressure, as well as the influences of Mg quantity on the pore size, porosity and mechanical properties of Al-Mg alloy were investigated. The results show that a higher pressure of solidification tends to yield smaller pores in aluminum and its alloys. In the case of Al-Mg alloys, it was proved that with the increasing of Mg amount, the mechanical properties of the alloys sharply deteriorate. However, since Al-3%Mg and Al-6wt.%Mg alloys are ductile metals, their porous samples have greater compressive strength than that of the dense samples due to the existence of pores. It gives the opportunity to use them in industry at the same conditions as dense alloys with savings in weight and material consumption.

  8. Ultrasensitive determination of mercury in human saliva by atomic fluorescence spectrometry based on solidified floating organic drop microextraction

    International Nuclear Information System (INIS)

    Yuan, C.-G.; Wang, J.; Jin, Y.

    2012-01-01

    We report on a new, rapid and simple method for the determination of ultra-trace quantities of mercury ion in human saliva. It is based on solidified floating organic drop microextraction and detection by cold vapor atomic fluorescence spectrometry (CV-AFS). Mercury ion was complexed with diethyldithiocarbamate, and the hydrophobic complex was then extracted into fine droplets of 1-undecanol. By cooling in an ice bath after extraction, the droplets in solution solidify to form a single ball floating on the surface of solution. The solidified micro drop containing the mercury complex was then transferred for determination by CV-AFS. The effects of pH value, concentration of chelating reagent, quantity of 1-undecanol, sample volume, equilibration temperature and time were investigated. Under the optimum conditions, the preconcentration of a 25-mL sample is accomplished with an enrichment factor of 182. The limit of detection is 2.5 ng L -1 . The relative standard deviation for seven replicate determinations at 0.1 ng mL -1 level is 4.1%. The method was applied to the determination of mercury in saliva samples collected from four volunteers. Two volunteers having dental amalgam fillings had 0.4 ng mL -1 mercury in their saliva, whereas mercury was not detectable in the saliva of two volunteers who had no dental fillings. (author)

  9. Precipitation in as-solidified undercooled Ni-Si hypoeutectic alloy: Effect of non-equilibrium solidification

    International Nuclear Information System (INIS)

    Fan Kai; Liu Feng; Yang Gencang; Zhou Yaohe

    2011-01-01

    Highlights: → The solid solubility of Si atom in α-Ni matrix increased with undercooling in the as-solidified sample. → The effect of non-equilibrium solidification on precipitation has been theoretically described. → The nucleation density, the real-time particle size and the precipitation rate are all increased upon annealing. → The precipitate process can be artificially controlled by modifying the initial melt undercooling and the annealing time. - Abstract: Applying glass fluxing and cyclic superheating, high undercooling up to ∼350 K was achieved for Ni-Si hypoeutectic alloy melt. By isothermally annealing the as-solidified alloy subjected to different undercoolings, precipitation behavior of Ni 3 Si particle, at 973 K, was systematically studied. It was found that, the nucleation density and the real-time particle size, as well as the precipitation rate, were all increased, provided the sample was solidified subjected to higher undercooling. This was ascribed mainly to the increased solid solubility of Si atom in α-Ni matrix upon non-equilibrium solidification. On this basis, the non-equilibrium dendrite growth upon solidification and the soft impingement prevailing upon solid-state precipitation have been quantitatively connected. As such, the effect of liquid/solid transformation on subsequent precipitation was described.

  10. Development of methodology to evaluate microbially influenced degradation of cement-solidified low-level radioactive waste forms

    International Nuclear Information System (INIS)

    Rogers, R.D.; Hamilton, M.A.; Veeh, R.H.; McConnell, J.W.

    1994-01-01

    Because of its apparent structural integrity, cement has been widely used in the United States as a binder to solidify Class B and C low-level radioactive waste (LLW). However, the resulting cement preparations are susceptible to failure due to the actions of stress and environment. An environmentally mediated process that could affect cement stability is the action of naturally occurring microorganisms. The US Nuclear Regulatory Commission (NRC), recognizing this eventuality, stated that the effects of microbial action on waste form integrity must be addressed. This paper provides present results from an ongoing program that addresses the effects of microbially influenced degradation (MID) on cement-solidified LLW. Data are provided on the development of an evaluation method using acid-producing bacteria. Results are from work with one type of these bacteria, the sulfur-oxidizing Thiobacillus. This work involved the use of a system in which laboratory- and vendor-manufactured, simulated waste forms were exposed on an intermittent basis to media containing thiobacilli. Testing demonstrated that MID has the potential to severely compromise the structural integrity of ion-exchange resin and evaporator-bottoms waste that is solidified with cement. In addition, it was found that a significant percentage of calcium and other elements were leached from the treated waste forms. Also, the surface pH of the treated specimens decreased to below 2. These conditions apparently contributed to the physical deterioration of simulated waste forms after 60 days of exposure to the thiobacilli

  11. Precipitation in as-solidified undercooled Ni-Si hypoeutectic alloy: Effect of non-equilibrium solidification

    Energy Technology Data Exchange (ETDEWEB)

    Fan Kai [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Liu Feng, E-mail: liufeng@nwpu.edu.cn [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China); Yang Gencang; Zhou Yaohe [State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi' an, Shaanxi 710072 (China)

    2011-08-25

    Highlights: {yields} The solid solubility of Si atom in {alpha}-Ni matrix increased with undercooling in the as-solidified sample. {yields} The effect of non-equilibrium solidification on precipitation has been theoretically described. {yields} The nucleation density, the real-time particle size and the precipitation rate are all increased upon annealing. {yields} The precipitate process can be artificially controlled by modifying the initial melt undercooling and the annealing time. - Abstract: Applying glass fluxing and cyclic superheating, high undercooling up to {approx}350 K was achieved for Ni-Si hypoeutectic alloy melt. By isothermally annealing the as-solidified alloy subjected to different undercoolings, precipitation behavior of Ni{sub 3}Si particle, at 973 K, was systematically studied. It was found that, the nucleation density and the real-time particle size, as well as the precipitation rate, were all increased, provided the sample was solidified subjected to higher undercooling. This was ascribed mainly to the increased solid solubility of Si atom in {alpha}-Ni matrix upon non-equilibrium solidification. On this basis, the non-equilibrium dendrite growth upon solidification and the soft impingement prevailing upon solid-state precipitation have been quantitatively connected. As such, the effect of liquid/solid transformation on subsequent precipitation was described.

  12. Evaluation of physical stability and leachability of Portland Pozzolona Cement (PPC) solidified chemical sludge generated from textile wastewater treatment plants

    International Nuclear Information System (INIS)

    Patel, Hema; Pandey, Suneel

    2012-01-01

    Highlights: ► Stabilization/solidification of chemical sludge from textile wastewater treatment plants using Portland Pozzolona Cement (PPC) containing fly ash. ► Physical engineering (compressive strength and block density) indicates that sludge has potential to be reused for construction purpose after stabilization/solidification. ► Leaching of heavy metals from stabilized/solidified materials were within stipulated limits. ► There is a modification of microstructural properties of PPC with sludge addition as indicated by XRD and SEM patterns. - Abstract: The chemical sludge generated from the treatment of textile dyeing wastewater is a hazardous waste as per Indian Hazardous Waste Management rules. In this paper, stabilization/solidification of chemical sludge was carried out to explore its reuse potential in the construction materials. Portland Pozzolona Cement (PPC) was selected as the binder system which is commercially available cement with 10–25% fly ash interground in it. The stabilized/solidified blocks were evaluated in terms of unconfined compressive strength, block density and leaching of heavy metals. The compressive strength (3.62–33.62 MPa) and block density (1222.17–1688.72 kg/m 3 ) values as well as the negligible leaching of heavy metals from the stabilized/solidified blocks indicate that there is a potential of its use for structural and non-structural applications.

  13. Microstructure and Tensile/Corrosion Properties Relationships of Directionally Solidified Al-Cu-Ni Alloys

    Science.gov (United States)

    Rodrigues, Adilson V.; Lima, Thiago S.; Vida, Talita A.; Brito, Crystopher; Garcia, Amauri; Cheung, Noé

    2018-03-01

    Al-Cu-Ni alloys are of scientific and technological interest due to high strength/high temperature applications, based on the reinforcement originated from the interaction between the Al-rich phase and intermetallic composites. The nature, morphology, size, volume fraction and dispersion of IMCs particles throughout the Al-rich matrix are important factors determining the resulting mechanical and chemical properties. The present work aims to evaluate the effect of the addition of 1wt%Ni into Al-5wt%Cu and Al-15wt%Cu alloys on the solidification rate, macrosegregation, microstructure features and the interrelations of such characteristics on tensile and corrosion properties. A directional solidification technique is used permitting a wide range of microstructural scales to be examined. Experimental growth laws relating the primary and secondary dendritic spacings to growth rate and solidification cooling rate are proposed, and Hall-Petch type equations are derived relating the ultimate tensile strength and elongation to the primary dendritic spacing. Considering a compromise between ultimate tensile strength and corrosion resistance of the examined alloys samples from both alloys castings it is shown that the samples having more refined microstructures are associated with the highest values of such properties.

  14. Electrochemical corrosion of Pb-1 wt% Sn and Pb-2.5 wt% Sn alloys for lead-acid battery applications

    Energy Technology Data Exchange (ETDEWEB)

    Osorio, Wislei R.; Peixoto, Leandro C.; Garcia, Amauri [Department of Materials Engineering, State University of Campinas - UNICAMP, PO Box 612, 13083-970 Campinas, SP (Brazil)

    2009-12-01

    The aim of this study was to compare the electrochemical corrosion behavior of as-cast Pb-1 wt% Sn and Pb-2.5 wt% Sn alloy samples in a 0.5 M H{sub 2}SO{sub 4} solution at 25 C. A water-cooled unidirectional solidification system was used to obtain the as-cast samples. Electrochemical impedance spectroscopy (EIS) diagrams, potentiodynamic polarization curves and an equivalent circuit analysis were used to evaluate the electrochemical corrosion response. It was found that a coarse cellular array has a better electrochemical corrosion resistance than fine cells. The pre-programming of microstructure cell size of Pb-Sn alloys can be used as an alternative way to produce as-cast components of lead-acid batteries with higher corrosion resistance associated with environmental and economical aspects. (author)

  15. Wear properties of Ti-13Zr-13Nb (wt.%) near β titanium alloy containing 0.5 wt.% boron in dry condition, Hank's solution and bovine serum

    International Nuclear Information System (INIS)

    Majumdar, P.; Singh, S.B.; Chakraborty, M.

    2010-01-01

    The effect of heat treatment on the microstructure, hardness and sliding wear behaviour of Ti-13Zr-13Nb (wt.%) containing 0.5 wt.% B (TZNB) has been studied and compared with that of Ti-13Zr-13Nb (wt.%) (TZN) alloy. The wear properties were tested in dry condition and in simulated body fluid (Hank's solution and bovine serum) to understand the effect of different medium on wear behaviour of the TZNB alloy. Depending on the heat treatment condition the microstructure of the alloy consisted of α/martensite and TiB in β matrix. In general, the hardness of all the heat treated samples varied in a narrow range and in most of the cases addition of boron to the TZN alloy decreased the hardness. Almost all cases, no significant variation of the wear rate in dry condition with heat treatment was observed. Compared with the wear rate in dry condition, the wear rate in Hank's solution of the all the TZNB samples increased substantially. Moreover, the wear was found to be most severe in bovine serum. Addition of boron to TZN alloy did not result in any improvement in the wear resistance in all the media studied.

  16. White matter fiber-based analysis of T1w/T2w ratio map

    Science.gov (United States)

    Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D.; Entringer, Sonja; Buss, Claudia; Styner, Martin

    2017-02-01

    Purpose: To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. Background: The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. Methods: We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. Results: We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

  17. White Matter Fiber-based Analysis of T1w/T2w Ratio Map.

    Science.gov (United States)

    Chen, Haiwei; Budin, Francois; Noel, Jean; Prieto, Juan Carlos; Gilmore, John; Rasmussen, Jerod; Wadhwa, Pathik D; Entringer, Sonja; Buss, Claudia; Styner, Martin

    2017-02-01

    To develop, test, evaluate and apply a novel tool for the white matter fiber-based analysis of T1w/T2w ratio maps quantifying myelin content. The cerebral white matter in the human brain develops from a mostly non-myelinated state to a nearly fully mature white matter myelination within the first few years of life. High resolution T1w/T2w ratio maps are believed to be effective in quantitatively estimating myelin content on a voxel-wise basis. We propose the use of a fiber-tract-based analysis of such T1w/T2w ratio data, as it allows us to separate fiber bundles that a common regional analysis imprecisely groups together, and to associate effects to specific tracts rather than large, broad regions. We developed an intuitive, open source tool to facilitate such fiber-based studies of T1w/T2w ratio maps. Via its Graphical User Interface (GUI) the tool is accessible to non-technical users. The framework uses calibrated T1w/T2w ratio maps and a prior fiber atlas as an input to generate profiles of T1w/T2w values. The resulting fiber profiles are used in a statistical analysis that performs along-tract functional statistical analysis. We applied this approach to a preliminary study of early brain development in neonates. We developed an open-source tool for the fiber based analysis of T1w/T2w ratio maps and tested it in a study of brain development.

  18. Feasibility of Cancer Immunotherapy with WT1 Peptide Vaccination for Solid and Hematological Malignancies in Children.

    Science.gov (United States)

    Sawada, Akihisa; Inoue, Masami; Kondo, Osamu; Yamada-Nakata, Kayo; Ishihara, Takashi; Kuwae, Yuko; Nishikawa, Masanori; Ammori, Yasuhiro; Tsuboi, Akihiro; Oji, Yusuke; Koyama-Sato, Maho; Oka, Yoshihiro; Yasui, Masahiro; Sugiyama, Haruo; Kawa, Keisei

    2016-02-01

    Advances in cancer immunotherapy in the pediatric field are needed in order to improve the prognosis of children with malignancies. We conducted a prospective phase I/II study of WT1 peptide vaccination for children with relapsed or refractory malignancies. The main eligibility criteria were affected tissues or leukemic cells expressing the WT1 gene, and patients (and donors for allogeneic hematopoietic stem cell transplantation) having HLA-A*24:02. Vaccination using the WT1 peptide (CYTWNQMNL), which was modified for higher affinity to this HLA-type molecule with the adjuvant Montanide ISA51, was performed weekly 12 times. Twenty-six patients were enrolled and 13 (50.0%) completed the vaccination 12 times. Evidence for the induction of WT1-specific cytotoxic T-lymphocyte (CTL) responses without severe systemic side effects was obtained. Two out of 12 patients with bulky disease exhibited a transient clinical effect (one mixed response and one stable disease), three out of six patients with minimal residual disease achieved transient molecular remission, and five out of eight patients without a detectable level of the molecular marker, but with a high risk of relapse, had the best outcome of long-term continuous complete remission. WT1 vaccination is a safe immunotherapy and induced WT1-specific CTL responses in children; however, as a single agent, vaccination only provided patients in remission, but with a high risk of relapse, with "long-term benefits" in the context of its use for relapse prevention. WT1 peptide-based treatments in combination with other modalities, such as anti-tumor drugs or immunomodulating agents, need to be planned. © 2015 Wiley Periodicals, Inc.

  19. On the use of rhodamine WT for the characterization of stream hydrodynamics and transient storage

    Science.gov (United States)

    Runkel, Robert L.

    2015-01-01

    Recent advances in fluorometry have led to increased use of rhodamine WT as a tracer in streams and rivers. In light of this increased use, a review of the dye's behavior in freshwater systems is presented. Studies in the groundwater literature indicate that rhodamine WT is transported nonconservatively, with sorption removing substantial amounts of tracer mass. Column studies document a two-step breakthrough curve in which two structural isomers are chromatographically separated. Although the potential for nonconservative transport is acknowledged in the surface water literature, many studies assume that sorptive losses will not affect the characterization of physical transport processes. A literature review and modeling analysis indicates that this assumption is valid for quantification of physical properties that are based on the bulk of the tracer mass (traveltime), and invalid for the characterization of processes represented by the tracer tail (transient storage attributable to hyporheic exchange). Rhodamine WT should be considered nonconservative in the hyporheic zone due to nonconservative behavior demonstrated for similar conditions in groundwater. As such, rhodamine WT should not be used as a quantitative tracer in hyporheic zone investigations, including the study of long flow paths and the development of models describing hyporheic zone processes. Rhodamine WT may be used to qualitatively characterize storage in large systems, where there are few practical alternatives. Qualitative investigations should rely on early portions of the tracer profile, making use of the temporal resolution afforded by in situ fluorometry, while discarding later parts of the tracer profile that are adversely affected by sorption.

  20. Fabrication and properties of strip casting 4.5 wt% Si steel thin sheet

    Energy Technology Data Exchange (ETDEWEB)

    Zu, Guoqing, E-mail: gz854@uowmail.edu.au [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Zhang, Xiaoming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Zhao, Jingwei [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Wang, Yuqian [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Yan, Yi [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia); Li, Chengang; Cao, Guangming [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Jiang, Zhengyi [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, NSW 2522 (Australia)

    2017-02-15

    Three 4.5 wt% Si steel thin sheets with different thicknesses were efficiently fabricated by twin-roll strip casting, warm rolling and cold rolling followed by final annealing. A comprehensive investigation from the workability of the as-cast strip to the magnetic property of the produces was performed to illustrate the superiority of the new materials. The results show that the as-cast strip, which has a much lower Vickers hardness than that of the 6.5 wt% Si steel, is suitable for rolling processing. The X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies confirm that no ordering phase exists in the as-cast strip. The cold-rolled thin sheets exhibit good surface quality without edge cracks. Furthermore, all the three 4.5 wt% Si steel thin sheets possess relative strong <100>//ND texture and present high magnetic inductions and low iron losses after finial annealing. - Highlights: • 4.5 wt% Si as-cast sheet with excellent workability was produced by strip casting. • Three 4.5 wt% Si thin sheets were effectively fabricated by warm and cold rolling. • The microstructure and macro-texture of the thin sheets were elucidated. • High magnetic inductions and low iron losses were achieved simultaneously.

  1. Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rong [Chongqing Jiaotong Univ., Chongqing (China). College of Materials Science and Engineering; Tang, Bin [Chongqing City Management College, Chongqing (China). Inst. of Finance and Trade; Gao, Tao [Sichuan Univ., Chengdu (China). Inst. of Atomic and Molecular Physics

    2017-09-01

    The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C{sub V} and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.

  2. Conceptual design study of Hyb-WT as fusion–fission hybrid reactor for waste transmutation

    International Nuclear Information System (INIS)

    Siddique, Muhammad Tariq; Kim, Myung Hyun

    2014-01-01

    Highlights: • Conceptual design study of fusion-fission hybrid reactor for waste transmutation. • MCNPX and MONTEBURNS are compared for transmutation performance of WT-Hyb. • Detailed neutronic performance of final optimized Hyb-WT design is analyzed. • A new tube-in-duct core design is implemented and compared with pin type design. • Study shows many aspects of hybrid reactor even though scope was limited to neutronic analysis. - Abstract: This study proposes a conceptual design of a hybrid reactor for waste transmutation (Hyb-WT). The design of Hyb-WT is based on a low-power tokamak (less than 150 MWt) and an annular ring-shaped reactor core with metal fuel (TRU 60 w/o, Zr 40 w/o) and a fission product (FP) zone. The computational code systems MONTEBURNS and MCNPX2.6 are investigated for their suitability in evaluating the performance of Hyb-WT. The overall design performance of the proposed reactor is determined by considering pin-type and tube-in-duct core designs. The objective of such consideration is to explore the possibilities for enhanced transmutation with reduced wall loading from fusion neutrons and reduced transuranic (TRU) inventory. TRU and FP depletion is analyzed by calculating waste transmutation ratio, mass burned per full power year (in units of kg/fpy), and support ratio. The radio toxicity analysis of TRUs and FPs is performed by calculating the percentage of toxicity reduction in TRU and FP over a burn cycle

  3. Neutron diffraction study of the deformation mechanisms of the uranium-7 wt.% niobium shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W. [Los Alamos National Lab, Los Alamos, NM 87545 (United States)]. E-mail: dbrown@lanl.gov; Bourke, M.A.M. [Los Alamos National Lab, Los Alamos, NM 87545 (United States); Field, R.D. [Los Alamos National Lab, Los Alamos, NM 87545 (United States); Hults, W.L. [Los Alamos National Lab, Los Alamos, NM 87545 (United States); Teter, D.F. [Los Alamos National Lab, Los Alamos, NM 87545 (United States); Thoma, D.J. [Los Alamos National Lab, Los Alamos, NM 87545 (United States); Vogel, S.C. [Los Alamos National Lab, Los Alamos, NM 87545 (United States)

    2006-04-15

    The shape memory effect (SME) has been reported in the uranium-niobium alloy system in the region of the phase diagram surrounding U-6.5 wt.% Nb. In this regime, the material may have either an {alpha}'' monoclinic (U-6 wt.% Nb), or {gamma}{sup 0} tetragonal structure (U-7 wt.% Nb) and is two phase near 6.5 wt.% niobium. In situ neutron diffraction studies during uniaxial compressive loading of U-7 wt.% Nb indicate that strain in the recoverable region is accommodated by both motion of existing twin boundaries within {gamma}{sup 0}-phase and stress-induced phase transformation from the {gamma}{sup 0} to the {alpha}'' structure. The volume fraction of the {gamma}{sup 0}-phase decreases from 100% initially to {approx}26% after 4% total strain and some reversion is observed on release. The initial stress state of the stress-induced {alpha}'' grains will be discussed as well as the load sharing between the two phases.

  4. Microstructural and thermophysical properties of U–6 wt.%Zr alloy for fast reactor application

    International Nuclear Information System (INIS)

    Kaity, Santu; Banerjee, Joydipta; Nair, M.R.; Ravi, K.; Dash, Smruti; Kutty, T.R.G.; Kumar, Arun; Singh, R.P.

    2012-01-01

    Highlights: ► Characterization of U–6%Zr alloy prepared by injection casting route. ► Martensitic to non-martensitic transformation of U–6%Zr alloy occurs at 843 K. ► Specific heat versus temperature curve shows a phase transition at 845 K. ► Average coefficient of thermal expansion is 18.28 × 10 −6 K −1 (298–823 K). ► Hardness versus temperature plot shows a transition at 748 K. - Abstract: The microstructural and high temperature behavior of U–6 wt.%Zr alloy has been investigated in this study. U–6 wt.%Zr alloy sample for this study was prepared by following injection casting route. The thermophysical properties like coefficient of thermal expansion, specific heat, thermal conductivity of the above alloy were determined. The hot-hardness data of the U–6 wt.%Zr alloy was also generated from room temperature to 973 K. Apart from that, the fuel-clad chemical compatibility with T91 grade steel was also studied by diffusion couple experiment. No studies have been reported on U–6 wt.%Zr alloy. This paper aims at filling up the gap on characterization and thermophysical property evaluation of U–6 wt.%Zr alloy.

  5. Mechanical, dynamical and thermodynamic properties of Al-3wt%Mg from first principles

    International Nuclear Information System (INIS)

    Yang, Rong; Tang, Bin; Gao, Tao

    2017-01-01

    The mechanical, dynamical and thermodynamic properties of Al-3wt%Mg have been investigated using the first-principles method. The calculated structural parameter is in good agreement with previous works. Results for the elastic modulus, stress-strain relationships, ideal tensile and shear strengths are presented. Al-3wt%Mg is found to have larger moduli and higher strengths than Al, which is consistent with its exploitation in Al precipitate-hardening mechanisms. The partial density of states (PDOS) show that the partly covalent-like bonding through Al p-Mg s hybridization is the origin of excellent mechanical properties of Al-3wt%Mg. The phonon dispersion curves indicate that Al-3wt%Mg is dynamically stable at ambient pressure and 0 K. Furthermore, the Helmholtz free energy ΔF, the entropy S, the constant-volume specific heat C_V and the phonon contribution to the internal energy ΔE are predicted using the phonon density of states. We expect that our work can provide useful guidance to help with the performance of Al-3wt%Mg.

  6. Modeling of zinc solubility in stabilized/solidified electric arc furnace dust

    International Nuclear Information System (INIS)

    Fernandez-Olmo, Ignacio; Lasa, Cristina; Irabien, Angel

    2007-01-01

    Equilibrium models which attempt for the influence of pH on the solubility of metals can improve the dynamic leaching models developed to describe the long-term behavior of waste-derived forms. In addition, such models can be used to predict the concentration of metals in equilibrium leaching tests at a given pH. The aim of this work is to model the equilibrium concentration of Zn from untreated and stabilized/solidified (S/S) electric arc furnace dust (EAFD) using experimental data obtained from a pH-dependence leaching test (acid neutralization capacity, ANC). EAFD is a hazardous waste generated in electric arc furnace steel factories; it contains significant amounts of heavy metals such as Zn, Pb, Cr or Cd. EAFD from a local factory was characterized by X-ray fluorescence (XRF), acid digestion and X-ray diffraction (XRD). Zn and Fe were the main components while the XRD analysis revealed that zincite, zinc ferrite and hematite were the main crystalline phases. Different cement/EAFD formulations ranging from 7 to 20% dry weight of cement were prepared and subjected to the ANC leaching test. An amphoteric behavior of Zn was found from the pH dependence test. To model this behavior, the geochemical model Visual MINTEQ (VMINTEQ) was used. In addition to the geochemical model, an empirical model based on the dissolution of Zn in the acidic zone and the re-dissolution of zinc compounds in the alkaline zone was considered showing a similar prediction than that obtained with VMINTEQ. This empirical model seems to be more appropriate when the metal speciation is unknown, or when if known, the theoretical solid phases included in the database of VMINTEQ do not allow to describe the experimental data

  7. Solidified structure and leaching properties of metallurgical wastewater treatment sludge after solidification/stabilization process.

    Science.gov (United States)

    Radovanović, Dragana Đ; Kamberović, Željko J; Korać, Marija S; Rogan, Jelena R

    2016-01-01

    The presented study investigates solidification/stabilization process of hazardous heavy metals/arsenic sludge, generated after the treatment of the wastewater from a primary copper smelter. Fly ash and fly ash with addition of hydrated lime and Portland composite cement were studied as potential binders. The effectiveness of the process was evaluated by unconfined compressive strength (UCS) testing, leaching tests (EN 12457-4 and TCLP) and acid neutralization capacity (ANC) test. It was found that introduction of cement into the systems increased the UCS, led to reduced leaching of Cu, Ni and Zn, but had a negative effect on the ANC. Gradual addition of lime resulted in decreased UCS, significant reduction of metals leaching and high ANC, due to the excess of lime that remained unreacted in pozzolanic reaction. Stabilization of more than 99% of heavy metals and 90% of arsenic has been achieved. All the samples had UCS above required value for safe disposal. In addition to standard leaching tests, solidificates were exposed to atmospheric conditions during one year in order to determine the actual leaching level of metals in real environment. It can be concluded that the EN 12457-4 test is more similar to the real environmental conditions, while the TCLP test highly exaggerates the leaching of metals. The paper also presents results of differential acid neutralization (d-AN) analysis compared with mineralogical study done by scanning electron microscopy and X-ray diffraction analysis. The d-AN coupled with Eh-pH (Pourbaix) diagrams were proven to be a new effective method for analysis of amorphous solidified structure.

  8. Recycling stabilised/solidified drill cuttings for forage production in acidic soils.

    Science.gov (United States)

    Kogbara, Reginald B; Dumkhana, Bernard B; Ayotamuno, Josiah M; Okparanma, Reuben N

    2017-10-01

    Stabilisation/solidification (S/S), which involves fixation and immobilisation of contaminants using cementitious materials, is one method of treating drill cuttings before final fate. This work considers reuse of stabilised/solidified drill cuttings for forage production in acidic soils. It sought to improve the sustainability of S/S technique through supplementation with the phytoremediation potential of plants, eliminate the need for landfill disposal and reduce soil acidity for better plant growth. Drill cuttings with an initial total petroleum hydrocarbon (TPH) concentration of 17,125 mg kg -1 and low concentrations of metals were treated with 5%, 10%, and 20% cement dosages. The treated drill cuttings were reused in granular form for growing a forage, elephant grass (Pennisetum purpureum), after mixing with uncontaminated soil. The grasses were also grown in uncontaminated soil. The phytoremediation and growth potential of the plants was assessed over a 12-week period. A mix ratio of one part drill cuttings to three parts uncontaminated soil was required for active plant growth. The phytoremediation ability of elephant grass (alongside abiotic losses) reduced the TPH level (up to 8795 mg kg -1 ) in the soil-treated-drill cuttings mixtures below regulatory (1000 mg kg -1 ) levels. There were also decreased concentrations of metals. The grass showed better heights and leaf lengths in soil containing drill cuttings treated with 5% cement dosage than in uncontaminated soil. The results suggest that recycling S/S treated drill cuttings for forage production may be a potential end use of the treated waste. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    Science.gov (United States)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  10. Time-dependent performance of soil mix technology stabilized/solidified contaminated site soils.

    Science.gov (United States)

    Wang, Fei; Wang, Hailing; Al-Tabbaa, Abir

    2015-04-09

    This paper presents the strength and leaching performance of stabilized/solidified organic and inorganic contaminated site soil as a function of time and the effectiveness of modified clays applied in this project. Field trials of deep soil mixing application of stabilization/solidification (S/S) were performed at a site in Castleford in 2011. A number of binders and addictives were applied in this project including Portland cement (PC), ground granulated blastfurnace slag (GGBS), pulverised fuel ash (PFA), MgO and modified clays. Field trial samples were subjected to unconfined compressive strength (UCS), BS CN 12457 batch leaching test and the extraction of total organics at 28 days and 1.5 years after treatment. The results of UCS test show that the average strength values of mixes increased from 0-3250 kPa at 28 days to 250-4250 kPa at 1.5 years curing time. The BS EN 12457 leachate concentrations of all metals were well below their drinking water standard, except Ni in some mixes exceed its drinking water standard at 0.02 mg/l, suggesting that due to varied nature of binders, not all of them have the same efficiency in treating contaminated soil. The average leachate concentrations of total organics were in the range of 20-160 mg/l at 28 days after treatment and reduced to 18-140 mg/l at 1.5 years. In addition, organo clay (OC)/inorgano-organo clay (IOC) slurries used in this field trial were found to have a negative effect on the strength development, but were very effective in immobilizing heavy metals. The study also illustrates that the surfactants used to modify bentonite in this field trail were not suitable for the major organic pollutants exist in the site soil in this project. Copyright © 2015 Elsevier B.V. All rights reserved.

  11. Thermal expansion of ThO2-2 wt% UO2 by HT-XRD

    International Nuclear Information System (INIS)

    Tyagi, A.K.; Mathews, M.D.

    2000-01-01

    The linear thermal expansion of polycrystalline ThO 2 -2 wt% UO 2 has been investigated from room temperature to 1473 K in flowing helium atmosphere using high temperature X-ray diffractometry. ThO 2 -2 wt% UO 2 shows a marginally higher linear thermal expansion as compared to pure ThO 2 . The average linear and volume thermal expansion coefficients of ThO 2 -2 wt% UO 2 are found to be α-bar a =9.74x10 -6 K -1 and α-bar v =29.52x10 -6 K -1 (298-1473 K). This study will be useful in designing the nuclear reactor fuel assembly based on ThO 2

  12. Study of uranium - 20 Wt per cent plutonium-niobium alloys (1963)

    International Nuclear Information System (INIS)

    Abgrall, J.; Barthelemy, P.; Boucher, R.

    1963-01-01

    U-Pu-Nb alloys containing 20 wt per cent Pu and 10 - 20 - 30 - 40 - 50 or 60 wt per cent Nb have been studied principally to determine the feasibility of their use as fuel element. The fabrication, casting and homogenisation presented certain difficulties due specially to niobium. The transformation temperatures, thermal expansion coefficients and nature of phases have been determined by thermal analysis, dilatometry, micrography and X Rays diffraction. For similar compositions, U-Pu-Mo and U-Pu-Nb alloys have many common points concerning the presence of zeta phase (up to 40 wt per cent Nb), the coefficients of expansion, the good behaviour during thermal cycling and the good resistance to air oxidation in spite of zeta phase. In consequence, irradiation tests in EL 3 reactor (Saclay) will be carried out in the near future. (authors) [fr

  13. Concept of large scale PV-WT-PSH energy sources coupled with the national power system

    Directory of Open Access Journals (Sweden)

    Jurasz Jakub

    2017-01-01

    Full Text Available Intermittent/non-dispatchable energy sources are characterized by a significant variation of their energy yield over time. In majority of cases their role in energy systems is marginalized. However, even in Poland which is strongly dedicated to its hard and brown coal fired power plants, the wind generation in terms of installed capacity starts to play a significant role. This paper briefly introduces a concept of wind (WT and solar (PV powered pumped storage hydroelectricity (PSH which seems to be a viable option for solving the problem of the variable nature of PV and WT generation. Additionally we summarize the results of our so far conducted research on the integration of variable renewable energy sources (VRES to the energy systems and present conclusions which strictly refer to the prospects of large scale PV-WT-PSH operating as a part of the polish energy system.

  14. Studies of Wilms’ Tumor (WT1 Gene Expression in Adult Acute Leukemias in Singapore

    Directory of Open Access Journals (Sweden)

    Che Kang Lim

    2007-01-01

    Full Text Available Biomarkers provide certain values for diagnosis, monitor treatment effi cacy, or for the development of novel therapeutic approach for particular diseases. Thus, the identifi cation of specifi c of biomarkers for specifi c medical problems, including malignant diseases may be valuable in medical practice. In the study, we have used the Wilms’ tumor gene (WT1 as a biomarker to evaluate its expression in local adult patients with newly diagnosed acute leukemia, including both acute myeloid and lymphoid leukemias (AML and ALL.Aim: To investigate WT1 gene expression in adult patients with acute leukemia at diagnosis.Methods: Eighteen patients with acute leukemia diagnosed at Singapore General Hospital, Singapore, between September, 2004 and July, 2005 were included in this study. There were fifteen AML and three ALL cases aged from 18 to 71 years old. Total RNA and DNA was extracted from peripheral blood mononuclear cells (PBMCs. Expression of WT1 was detected by nested reverse-transcription polymerase chain reaction (Nested RT-PCR. K562, and 3T3 cells were used as positive- and negative-controls. The results were revalidated using real-time PCR. HLA-A genotyping was performed using sequence specific oligonucleotide polymorphism (SSOP analysis.Results: WT1 gene was exclusively expressed in all eighteen, including three ALL and fi fteen AML, patients. In contrast with WT1 gene, the HLA-A genotyping was remarkably heterogeneous in these patients.Conclusions: WT1 gene expression was observed in local patients with acute leukemia at diagnosis. It may be used as a potential molecular marker for diagnosis, clinical progression of the diseases or monitoring the response to treatment, as well as a target for the development of novel therapeutic approaches.

  15. Microstructure and adhesion strength of Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu after electrochemical polarization in a 3.5 wt% NaCl solution

    Energy Technology Data Exchange (ETDEWEB)

    Li, W.-L. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Institute of Nanotechnology and Microsystems Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Chen, Y.-R.; Chang, K.-M. [Department of Mechanical Engineering, National Kaohsiung University of Applied Sciences, 415 Chien-Kung Road, Kaohsiung 80782, Taiwan (China); Liu, C.-Y.; Hon, M.-H. [Department of Materials Science and Engineering, National Cheng Kung University, 1 Ta-Hsueh Road, Tainan 70101, Taiwan (China); Wang, M.-C. [Faculty of Fragrance and Cosmetics, Kaohsiung Medical University, 100 Shihchuan 1st Road, Kaohsiung 80728, Taiwan (China)], E-mail: mcwang@kmu.edu.tw

    2008-08-11

    The microstructure and adhesion strength of the Sn-9Zn-1.5Ag-xBi (x = 0 wt% and 2 wt%)/Cu interface after electrochemical polarization have been studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and pull-off testing. The equilibrium potentials of Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu are -1.31 V{sub sce} and -1.22 V{sub sce}, respectively, indicating that Sn-9Zn-1.5Ag-2Bi/Cu has a better corrosion resistance than that of Sn-9Zn-1.5Ag/Cu. The intermetallic compounds of Cu{sub 6}Sn{sub 5}, Cu{sub 5}Zn{sub 8} and Ag{sub 3}Sn are formed at the soldered interface between the Sn-9Zn-1.5Ag-xBi solder alloy and the Cu substrate. The scallop-shaped Cu{sub 6}Sn{sub 5} is close to the Cu substrate and the scallop-shaped Cu{sub 5}Zn{sub 8} is found at the interface in the solder matrix after soldering at 250 deg. C for 10 s. The corrosion products are ZnCl{sub 2}, SnCl{sub 2} and ZnO. On the other hand, pits are also formed on the surface of both solder alloys. The interfacial adhesion strength of the Sn-9Zn-1.5Ag/Cu and Sn-9Zn-1.5Ag-2Bi/Cu decreases from 8.27 {+-} 0.56 MPa and 12.67 {+-} 0.45 MPa to 4.78 {+-} 0.45 MPa and 8.14 {+-} 0.38 MPa, respectively, after electrochemical polarization in a 3.5 wt% NaCl solution. The fracture path of the Sn-9Zn-1.5Ag-2Bi/Cu is along the solder alloy/ZnO and solder/Cu{sub 6}Sn{sub 5} interfaces.

  16. Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jayaraman, T. V.; Meka, V. M.; Jiang, X.; Overman, N. R.; Doyle, J.; Shield, J. E.; Mathaudhu, S. N.

    2018-04-01

    In this work, we investigated the ambient temperature structural properties (~300 K) and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties of melt-spun Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The thickness, width, lattice parameter, saturation magnetization (MS), and intrinsic coercivity (HCI) of the melt spun ribbons are presented and compared with data in the literature. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbons ranged between ~15-60 μm and 500-800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel-surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). Wheel surface speed was not shown to have a significant effect on the magnetization, but primarily impacted the ribbon structure. A decreasing trend in the saturation magnetization was observed as a function of increased silicon content. The intrinsic coercivity of the melt-spun alloys ranged between ~50 to 200 A/m. Elevated temperature evaluation of the magnetization in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The MS for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 – 900 K). The percentage decrease in MS from 300 K to 900 K for the Fe-3 wt.% Si and Fe-5 wt.% Si alloys was ~19-22 %, while the percentage decrease in the same

  17. Characterization and assessment of voltage and power constraints of DFIG WT connected to a weak network

    DEFF Research Database (Denmark)

    Abulanwar, Elsayed; Hu, Weihao; Iov, Florin

    2014-01-01

    This article thoroughly investigates the challenges and constraints raised by the integration of a Doubly-fed Induction generator wind turbine, DFIG WT, into an ac network of extensively varying parameters and very weak conditions. The objective is to mitigate the voltage variations at the point...... of common coupling, PCC, and maximize the wind power penetration into weak networks. As a basis of investigation, a simplified system model is utilized and the respective PCC voltage, active and reactive power stability issues are identified. Besides, a steady-state study for DFIG WT connected to a weak...

  18. Review of Z phase precipitation in 9–12 wt-%Cr steels

    DEFF Research Database (Denmark)

    Danielsen, Hilmar Kjartansson

    2016-01-01

    For high temperature applications, 9–12 wt-%Cr steels in fossil fired power plants rely upon precipitate strengthening from (V,Nb)N MX nitrides for long term creep strength. During prolonged exposure at service temperature, another nitride precipitates: Cr(V,Nb)NZ phase. The Z phases lowly replace......MX, eventually causing a breakdown in creep strength. The present paper reviews the Z phase and its behaviour in 9–12 wt-%Cr steels including thermodynamic modelling, crystal structure, nucleation process and precipitation rate as a function of chemical composition. The influence of Z phase precipitation upon...

  19. Al/ B4C Composites with 5 and 10 wt% Reinforcement Content Prepared by Powder Metallurgy

    International Nuclear Information System (INIS)

    Yusof Abdullah; Mohd Reusmaazran Yusof; Azali Muhammad; Nadira Kamarudin; Wilfred Sylvester Paulus; Roslinda Shamsudin; Nasrat Hannah Shudin; Nurazila Mat Zali

    2012-01-01

    The preparation, physical and mechanical properties of Al/ B 4 C composites with 5 and 10 wt.% reinforcement content were investigated. In order to obtain the feedstock with a low powder loading, B 4 C mixtures containing fine powders were investigated to obtain the optimal particle packing. The experimental results indicated that the fine containing 5 and 10 wt.% particles are able to prepare the feedstock with a good flowability. The composites fabricated by powder metallurgy have low densities and homogeneous microstructures. Additionally there is no interface reaction observed between the reinforcement and matrix by XRD analysis. The hardness of Al/ B 4 C composites prepared by powder metallurgy was high. (Author)

  20. Effect of Heat Treatments on Microstructures and Tensile Properties of Cu-3 wt%Ag-0.5 wt%Zr Alloy

    Science.gov (United States)

    Chen, Gang; Wang, ChuanJie; Zhang, Ying; Yi, Cen; Zhang, Peng

    2018-03-01

    The microstructures and tensile properties of Cu-3 wt%Ag-0.5 wt%Zr alloy sheets under different aging treatments are investigated in this research. As one kind of precipitate, Ag nanoparticles with coherent orientation relationship with matrix precipitate. However, after the peak-age point, most of Ag nanoparticles grow into short rod shape with the interface translating to semi-coherent, which leads to the lower strength of over-aging sample. The yield strength is estimated by considering solid solute, grain boundary and precipitation strengthening mechanisms. The result shows that the Ag precipitates provide the main strengthening role. Then a constitutive equation representing the evolution of dislocation density with plastic strain is built by considering work-hardening behavior coming from shearable and non-shearable precipitates which is mainly the particles containing Zr. The flow stress contributed by shearable particle hardening is higher than that of non-shearable one. Due to the coarsening of grain boundary precipitates and low rate of damage accumulation of these non-shearable particles, the micro-cracks nucleate easily at grain boundary which leads to intergranular fracture.

  1. Effect of strain on evolution of dynamic recrystallization in Nb-1 wt%Zr-0.1 wt%C alloy at 1500 and 1600 °C

    Energy Technology Data Exchange (ETDEWEB)

    Behera, A.N. [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094 (India); Kapoor, R., E-mail: rkapoor@barc.gov.in [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Homi Bhabha National Institute, Anushakti Nagar, Mumbai 400094 (India); Paul, B. [Materials Processing & Corrosion Engineering Division, Bhabha Atomic Research Centre, Mumbai 400085 (India); Chakravartty, J.K. [Mechanical Metallurgy Division, Bhabha Atomic Research Centre, Mumbai 400085 (India)

    2017-04-15

    Uniaxial compression tests were carried out on Nb-1 wt%Zr-0.1 wt%C alloy at temperature of 1500 and 1600 °C and strain rate of 0.1 s{sup −1} to study the evolution of dynamic recrystallization with strain. Electron back scatter diffraction was used to quantify the microstructural evolution. Nb-1Zr-0.1C alloy showed a necklace structure at a strain of 0.9 when deformed at 1500 °C and at strain of 0.6 when deformed at 1600 °C, both at strain rate of 0.1 s{sup −1}. This suggested the occurrence of dynamic recrystallization. At 1500 °C and strain of 0.9 the local average misorientation and the grain orientation spread was low confirming the presence of dynamic recrystallization at this deformation condition. At both 1500 and 1600 °C and all measured strains the recrystallized grains had a strong fiber component of <001>. - Highlights: • Necklace formation of dynamically recrystallized grains occurred at strain of 0.6 and 0.9 for 1500 and 1600 °C, respectively. • Equiaxed microstructures were seen with increase in strain for both 1500 and 1600 °C. • At large strains the predominant recrystallized texture evolved to <001> pole.

  2. Crack initiation modeling of a directionally-solidified nickel-base superalloy

    Science.gov (United States)

    Gordon, Ali Page

    Combustion gas turbine components designed for application in electric power generation equipment are subject to periodic replacement as a result of cracking, damage, and mechanical property degeneration that render them unsafe for continued operation. In view of the significant costs associated with inspecting, servicing, and replacing damaged components, there has been much interest in developing models that not only predict service life, but also estimate the evolved microstructural state of the material. This thesis explains manifestations of microstructural damage mechanisms that facilitate fatigue crack nucleation in a newly-developed directionally-solidified (DS) Ni-base superalloy components exposed to elevated temperatures and high stresses. In this study, models were developed and validated for damage and life prediction using DS GTD-111 as the subject material. This material, proprietary to General Electric Energy, has a chemical composition and grain structure designed to withstand creep damage occurring in the first and second stage blades of gas-powered turbines. The service conditions in these components, which generally exceed 600°C, facilitate the onset of one or more damage mechanisms related to fatigue, creep, or environment. The study was divided into an empirical phase, which consisted of experimentally simulating service conditions in fatigue specimens, and a modeling phase, which entailed numerically simulating the stress-strain response of the material. Experiments have been carried out to simulate a variety of thermal, mechanical, and environmental operating conditions endured by longitudinally (L) and transversely (T) oriented DS GTD-111. Both in-phase and out-of-phase thermo-mechanical fatigue tests were conducted. In some cases, tests in extreme environments/temperatures were needed to isolate one or at most two of the mechanisms causing damage. Microstructural examinations were carried out via SEM and optical microscopy. A continuum

  3. Effect of La addition on the microstructure and mechanical properties of Mg–6 wt% Zn alloys

    Energy Technology Data Exchange (ETDEWEB)

    Du, Yuzhou, E-mail: duyuzhou@xaut.edu.cn [School of Materials Science and Engineering, Xi' an University of Technology, Xi' an 710048 (China); School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Zheng, Mingyi, E-mail: zhenghe@hit.edu.cn [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Qiao, Xiaoguang [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Peng, Wenqiang [Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621999 (China); Jiang, Bailing [School of Materials Science and Engineering, Xi' an University of Technology, Xi' an 710048 (China)

    2016-09-15

    The Mg–6 wt% Zn alloys microalloyed with different amounts of La were cast and extruded. The second phase in the as-cast Mg–Zn alloy is Mg{sub 4}Zn{sub 7}, which was replaced by Mg–Zn–La intermetallics with orthorhombic structure after La addition. Microalloying with La refined the grain size of dynamic recrystallization slightly, which was due to La solute atom in α-Mg alloy. Addition of La weakened the texture and gave rise to the formation of non-basal texture component, attributing to the existence of La in the form of solute atoms in matrix. The ductility was enhanced significantly by adding La to Mg–6 wt% Zn alloy, while the strength was reduced. Such phenomenon was related to the weakening texture of the La containing alloys. The Mg–6Zn–0.2La (wt%) alloy exhibited a superior ductility with the elongation-to-fracture up to 35%. However, with further increasing of La content to 1 wt%, the strength of the as-extruded Mg–Zn–La alloys was not improved but the ductility was reduced, suggesting that small addition of La is preferred for the improvement of mechanical properties.

  4. Effect of Thai saraphi flower extracts on WT1 and BCR/ABL protein ...

    African Journals Online (AJOL)

    In this study, the cytotoxic effects of crude ethanolic and fractional extracts including hexane, ethyl acetate, and methanol fractions from M. siamensis flowers were investigated in order to determine their effect on WT1 expression in Molt4 and K562 cells and Bcr/Abl expression in K562 cells. Materials and Methods: The ...

  5. Effect of Cu addition on the microstructure and mechanical properties of Al–30 wt% Zn alloy

    International Nuclear Information System (INIS)

    Abd El-Rehim, A.F.; Sakr, M.S.; El-Sayed, M.M.; Abd El-Hafez, M.

    2014-01-01

    Highlights: • This paper describes a novel work on the effect of Cu addition on the Al–30 wt% Zn alloy. • The 1 wt% Cu alloy revealed the best hardness of the alloys. • The results indicated two deformation temperature regions (below and above 548 K). - Abstract: The effect of 0.5, 1, 1.5 and 2 wt% Cu addition on the microstructure and mechanical properties of Al–30 wt% Zn alloy has been investigated by stress–strain tests carried out in the temperature range from 508 to 608 K. The work-hardening parameters of the test alloys decreased with increasing the deformation temperature and exhibited discontinuity at 548 K, resulting two deformation temperature regions, the low-temperature region (below 548 K) and high-temperature region (above 548 K). The activation energy of fracture mechanisms has been calculated and found to be 19.6 and 33.2 kJ/mol at the low and high temperature regions respectively. The operating mechanisms of work-hardening of the test alloys were confirmed by the analysis of X-ray diffraction patterns

  6. Reaction layer between U-7WT%Mo and Al alloys in chemical diffusion couples

    International Nuclear Information System (INIS)

    Mirandou, M.; Granovsky, M.; Ortiz, M.; Balart, S.; Arico, S.; Gribaudo, L.

    2005-01-01

    Several failures in U-Mo dispersion fuel plates like pillowing and large porosities have been reported during irradiation experiments. These failures have been assigned to the formation of a large (U-Mo)/Al interaction product under high operating conditions. The modification of the matrix by alloying Al to change the interaction layer and improve its irradiation behavior, has been proposed. This paper reports diffusion experiments performed between U-7wt%Mo and various Al alloys containing Mg and / or Si. By the use of Optical Microscopy, SEM and X-Ray diffraction, it was found that with a concentration of 5.2wt% or 7.1 wt%Si the interaction layer is constituted mainly by (U,Mo)(Si,Al) 3 and no (U,Mo)Al 4 is detected. As part of the studies of properties of the U-Mo alloys the time for isothermal transformation start at different temperatures of the γ phase is being evaluated for the present U-7wt%Mo alloy. These results are used to plan the future diffusion program that will include diffusion under irradiation at CNEA RA3 reactor. (author)

  7. Anomalous precipitation hardening in Al-(1 wt%)Cu thin films

    NARCIS (Netherlands)

    Bergers, L. J. C.; De Hosson, J. Th. M.; Geers, M. G. D.; Hoefnagels, J. P. M.

    2018-01-01

    This paper concentrates on the precipitation hardening of Al-(1 wt%)Cu thin films. It is shown that in contrast to bulk, the well-known approach of precipitation hardening in confined systems like thin layers and thin films does not operate in the conventional way. This work analyses and discusses

  8. ADAMS/WT advanced development - version 1.4 and beyond

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, A.S.; Depauw, T.R. [Mechanical Dynamics, Inc., Mesa, AZ (United States)

    1996-12-31

    ADAMS/WT is an wind-turbine-specific shell for the general-purpose mechanical system simulation package ADAMS5. It was developed under the guidance of the National Renewable Energy Laboratory to give engineers and analysts in the wind turbine community access to the analytical power of ADAMS, without having to become expert in its particular technology. The 1.4 version of ADAMS/WT is the most recent upgrade to the package, incorporating the most up-to-date version of the AeroDyn aerodynamic forcing subroutines from the University of Utah. It is also the first version to be made available on the Windows/NT platform. In version 1.4, ADAMS/WT has been significantly improved throughout and runs much faster. Automatic generation of standardized output has been added. The documentation has been extensively augmented with more detailed descriptions, more figures and more examples. ADAMS/WT remains the most powerful analytical tool available for horizontal-axis wind turbine development. 10 figs.

  9. Diagnostic utility of Wilms′ tumour-1 protein (WT-1 immunostaining in paediatric renal tumours

    Directory of Open Access Journals (Sweden)

    Surbhi Goyal

    2016-01-01

    Interpretation & conclusions: WT1 helps to differentiate Wilms′ tumour from other paediatric renal tumours. It may help in differentiating the two subgroups of Wilms′ tumour which have distinct molecular pathogenesis and biological behaviour, however, further prospective studies are required for validation of this hypothesis.

  10. Hot drawn Fe–6.5 wt.%Si wires with good ductility

    International Nuclear Information System (INIS)

    Yang, W.; Li, H.; Yang, K.; Liang, Y.F.; Yang, J.; Ye, F.

    2014-01-01

    Highlights: • Fe–6.5wt%Si steel wire with diameter of 1.6 mm can be successfully obtained by hot drawing process. • The ductility of Fe–6.5wt%Si alloy can be improved significantly when it is fabricated in the form of wire. • The Dc magnetic property of Fe–6.5wt%Si steel wire 1.6 mm in diameter is excellent, which is close to that of 0.3 mm thick cold-rolling sheet. - Abstract: Fe–6.5 wt.%Si high silicon steel wires with a diameter of 1.6 mm are fabricated successfully by hot drawing. The high silicon steel wires show much better ductility than sheets. The tensile strength and elongation of the wires at the room temperature can reach 1.31 GPa and 1.4%, respectively. The tensile strength and elongation of the rolling sheet at the room temperature are 0.8 GPa and 0, respectively. The microstructure analyses show that the elongated grains after drawing and reduced ordering phases by deformation in the wires might contribute to its good ductility. Bs value of 1.437 T and Hc value of 16.96 A/m are obtained for the wire after proper heat treatment for the wires

  11. Methodological approach to simulation and choice of ecologically efficient and energetically economic wind turbines (WT)

    Science.gov (United States)

    Bespalov, Vadim; Udina, Natalya; Samarskaya, Natalya

    2017-10-01

    Use of wind energy is related to one of the prospective directions among renewed energy sources. A methodological approach is reviewed in the article to simulation and choice of ecologically efficient and energetically economic wind turbines on the designing stage taking into account characteristics of natural-territorial complex and peculiarities of anthropogenic load in the territory of WT location.

  12. Dendritic coarsening of γ' phase in a directionally solidified superalloy during 24,000 h of exposure at 1173 K

    International Nuclear Information System (INIS)

    Li, H.; Wang, L.; Lou, L.H.

    2010-01-01

    Dendritic coarsening of γ' was investigated in a directionally solidified Ni-base superalloy during exposure at 1173 K for 24,000 h. Chemical homogeneity along different directions and residual internal strain in the experimental superalloy were measured by electronic probe microanalysis (EPMA) and electron back-scattered diffraction (EBSD) technique. It was indicated that the gradient of element distribution was anisotropic and the inner strain between dendrite core and interdendritic regions was different even after 24,000 h of exposure at 1173 K, which influenced the kinetics for the dendrite coarsening of γ' phase.

  13. Studies of the Influence of Beam Profile and Cooling Conditions on the Laser Deposition of a Directionally-Solidified Superalloy

    Directory of Open Access Journals (Sweden)

    Shuo Yang

    2018-02-01

    Full Text Available In the laser deposition of single crystal and directionally-solidified superalloys, it is desired to form laser deposits with high volume fractions of columnar grains by suppressing the columnar-to-equiaxed transition efficiently. In this paper, the influence of beam profile (circular and square shapes and cooling conditions (natural cooling and forced cooling on the geometric morphology and microstructure of deposits were experimentally studied in the laser deposition of a directionally-solidified superalloy, IC10, and the mechanisms of influence were revealed through a numerical simulation of the thermal processes during laser deposition. The results show that wider and thinner deposits were obtained with the square laser beam than those with the circular laser beam, regardless of whether natural or forced cooling conditions was used. The heights and contact angles of deposits were notably increased due to the reduced substrate temperatures by the application of forced cooling for both laser beam profiles. Under natural cooling conditions, columnar grains formed epitaxially at both the center and the edges of the deposits with the square laser beam, but only at the center of the deposits with the circular laser beam; under forced cooling conditions, columnar grains formed at both the center and the edges of deposits regardless of the laser beam profile. The high ratios of thermal gradient and solidification velocity in the height direction of the deposits were favorable to forming deposits with higher volume fractions of columnar grains.

  14. Printing low-melting-point alloy ink to directly make a solidified circuit or functional device with a heating pen.

    Science.gov (United States)

    Wang, Lei; Liu, Jing

    2014-12-08

    A new method to directly print out a solidified electronic circuit through low-melting-point metal ink is proposed. A functional pen with heating capability was fabricated. Several typical thermal properties of the alloy ink Bi 35 In 48.6 Sn 16 Zn 0.4 were measured and evaluated. Owing to the specifically selected melting point of the ink, which is slightly higher than room temperature, various electronic devices, graphics or circuits can be manufactured in a short period of time and then rapidly solidified by cooling in the surrounding air. The liquid-solid phase change mechanism of the written lines was experimentally characterized using a scanning electron microscope. In order to determine the matching substrate, wettability between the metal ink Bi 35 In 48.6 Sn 16 Zn 0.4 and several materials, including mica plate and silicone rubber, was investigated. The resistance-temperature curve of a printed resistor indicated its potential as a temperature control switch. Furthermore, the measured reflection coefficient of a printed double-diamond antenna accords well with the simulated result. With unique merits such as no pollution, no requirement for encapsulation and easy recycling, the present printing approach is an important supplement to current printed electronics and has enormous practical value in the future.

  15. Cold Heat Release Characteristics of Solidified Oil Droplet-Water Solution Latent Heat Emulsion by Air Bubbles

    Science.gov (United States)

    Inaba, Hideo; Morita, Shin-Ichi

    The present work investigates the cold heat-release characteristics of the solidified oil droplets (tetradecane, C14H30, freezing point 278.9 K)/water solution emulsion as a latent heat-storage material having a low melting point. An air bubbles-emulsion direct-contact heat exchange method is selected for the cold heat-results from the solidified oil droplet-emulsion layer. This type of direct-contact method results in the high thermal efficiency. The diameter of air bubbles in the emulsion increases as compared with that in the pure water. The air bubbles blown from a nozzle show a strong mixing behavior during rising in the emulsion. The temperature effectiveness, the sensible heat release time and the latent heat release time have been measured as experimental parameters. The useful nondimensional emulsion level equations for these parameters have been derived in terms of the nondimensional emalsion level expressed the emulsion layer dimensions, Reynolds number for air flow, Stefan number and heat capacity ratio.

  16. Leach studies on cement-solidified ion exchange resins from decontamination processes at operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.; Morcos, N.

    1992-01-01

    The effects of varying pH and leachant compositions on the physical stability and leachability of radionuclides and chelating agents were determined for cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small scale waste-form specimens were collected during waste solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station. The collected specimens were leach tested, and their compressive strength was measured in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1), from the Low-Level Waste Management Branch. Leachates from these studies were analyzed for radionuclides, selected transition metals, and chelating agents to assess the leachability of these waste form constituents. Leachants used for the study were deionized water, simulated seawater, and groundwater compositions similar to those found at Barnwell, South Carolina and Hanford, Washington. Results of this study indicate that initial leachant pH does not affect leachate pH or releases from cement-solidified decontamination ion-exchange resin waste forms. However, differences in leachant composition and the presence of chelating agents may affect the releases of radionuclides and chelating agents. In addition, results from this study indicate that the cumulative releases of radionuclides and chelating agents observed for forms that disintegrated were similar to those for forms that maintained their general physical integrity

  17. Nial and Nial-Based Composites Directionally Solidified by a Containerless Zone Process. Ph.D. Thesis

    Science.gov (United States)

    Joslin, Steven M.

    1995-01-01

    A containerless electromagnetically levitated zone (CELZ) process has been used to directionally solidify NiAl and NiAl-based composites. The CELZ processing results in single crystal NiAl (HP-NiAl) having higher purity than commercially pure NiAl grown by a modified Bridgman process (CP-NiAl). The mechanical properties, specifically fracture toughness and creep strength, of the HP-NiAl are superior to binary CP-NiAl and are used as a base-line for comparison with the composite materials subsequently studied. Two-phase composite materials (NiAl-based eutectic alloys) show improvement in room temperature fracture toughness and 1200 to 1400 K creep strength over that of binary HP-NiAl. Metallic phase reinforcements produce the greatest improvement in fracture toughness, while intermetallic reinforcement produces the largest improvement in high temperature strength. Three-phase eutectic alloys and composite materials were identified and directionally solidified with the intent to combine the improvements observed in the two-phase alloys into one alloy. The room temperature fracture toughness and high temperature strength (in air) serve as the basis for comparison between all of the alloys. Finally, the composite materials are discussed in terms of dominant fracture mechanism observed by fractography.

  18. irradiation growth in annealed Zr2.5wt%Nb at 3530K

    International Nuclear Information System (INIS)

    Rogerson, A.; Murgatroyd, R.A.

    1978-10-01

    Zr 2.5wt%Nb growth specimens have been irradiated at 353 0 K to a fast neutron dose of approximately 4.0 x 10 25 n/m 2 . Specimens were taken from the longitudinal and transverse directions of a nominally annealed, seam-welded tube and irradiated in both the stress relieved and fully annealed conditions. Growth in these specimens is characterised by large positive and negative strains in the longitudinal and transverse directions respectively, with dimensional changes in weld material exhibiting intermediate growth behaviour. The results are compared with growth data on both annealed and cold worked Zircaloy-2 at 353 0 K and discussed in terms of the effect of texture, grain size, and cold work on irradiation growth. It is concluded that the continuation of growth to high doses in annealed Zr-2.5wt%Nb at 353 0 K results from interstitial induced dislocation climb with vacancies diffusing to grain boundaries. (author)

  19. Work hardening characteristics in Al base alloys with 12.6 and 45 wt.% Zn

    International Nuclear Information System (INIS)

    Abd El-Salam, F.; Mostafa, M.M.; Wahab, L.A.; Mostafa, M.T.; Abd El-Aziz, Sh.M.

    2008-01-01

    The stress-strain curves were obtained for Al-Zn alloys of 12.6 wt.% Zn (alloy I) and 45 wt.% Zn (alloy II) with elements of purity (99.99). The monotonic shift of these curves towards lower flow stress and higher ductility was interrupted at the transformation temperatures 483 K (alloy I) and both 543, 603 K (alloy II). By increasing deformation temperature, Young's modulus, Y, yield and fracture stresses, σ y and σ f , respectively, fracture time, t f , the coefficient of parabolic work hardening, χ, decreased while fracture strain, ε f , and dislocation slip distance, L, increased. From the obtained X-rays diffraction patterns the lattice strain, ε, crystallite size, η, and dislocation density, ρ, were obtained at different deformation temperatures around transformation

  20. Metallurgical characterization of melt-spun ribbons of U-5.4 wt%Nb alloy

    Science.gov (United States)

    Ma, Rong; Ren, Zhiyong; Tang, Qingfu; Chen, Dong; Liu, Tingyi; Su, Bin; Wang, Zhenhong; Luo, Chao

    2018-06-01

    The microstructures and micro-mechanical properties of the melt-spun ribbons of U-5.4 wt%Nb alloy were characterized using optical microscopy, scanning electron microscopy, X-ray diffraction and nanoindentation. Observed variations in microstructures and properties are related to the changes in ribbon thicknesses and cooling rates. The microstructures of the melt-spun ribbon consist of fine-scale columnar grains (∼1 μm) adjacent to the chill surface and coarse cellular grains in the remainder of the ribbon. In addition, the formation of inclusions in the ribbon is suppressed kinetically due to the high cooling rate during melt spinning. Compared with the water-quenched specimen prepared by traditional gravity casting and solution heat treatment, the elastic modulus values of the U-5.4 wt%Nb alloy were examined to vary with grain size and exhibited diverse energy dissipation capacities.

  1. Critical experiments on minimal-content gadolinia for above-5wt% enrichment fuels in Toshiba NCA

    International Nuclear Information System (INIS)

    Kikuchi, Tsukasa; Watanabe, Shouichi; Yoshioka, Kenichi; Mitsuhashi, Ishi; Kumanomido, Hironori; Sugahara, Satoshi; Hiraiwa, Kouji

    2009-01-01

    A concept of 'minimal-content gadolinia' with a content of less than several hundred ppm mixed in the 'above-5wt% enrichment UO 2 fuel' for super high burnup is proposed for ensuring the criticality safety in the UO 2 fuel fabrication facility for light water reactors (LWRs) without increase in investment cost. Required gadolinia contents calculated were from 53 to 305 ppm for enrichments of UO 2 powders for boiling water reactor (BWR) fuel from 6 to 10 wt%. It is expected that the minimal-content gadolinia yields an acceptable reactivity suppression at the beginning of operating cycle and no reactivity penalty at the end of operating cycle due to no residual gadolinium. A series of critical experiments were carried out in the Toshiba Nuclear Critical Assembly (NCA). Reactivity effects of the gadolinia were measured to clarify the nuclear characteristics, and the measured values and the calculated values agreed within 5%. (author)

  2. Achados clínicos e genéticos de cinco pacientes com anomalias relacionadas ao gene WT1

    OpenAIRE

    Andrade, Juliana Gabriel R. de; Guaragna, Mara Sanches; Soardi, Fernanda Caroline; Guerra-Júnior, Gil; Mello, Maricilda Palandi de; Maciel-Guerra, Andréa Trevas

    2008-01-01

    AIM: To present phenotypic variability of WT1-related disorders. METHODS: Description of clinical and genetic features of five 46,XY patients with WT1 anomalies. RESULTS: Patient 1: newborn with genital ambiguity; he developed Wilms tumor (WT) and chronic renal disease and died at the age of 10 months; the heterozygous 1186G>A mutation compatible with Denys-Drash syndrome was detected in this child. Patients 2 and 3: adolescents with chronic renal disease, primary amenorrhea and hypergonadotr...

  3. Setting of cesium residual ratio of molten solidified waste produced in Japan Atomic Power Company Tokai and Tokai No.2 Power Stations

    International Nuclear Information System (INIS)

    2013-02-01

    JNES investigated the appropriateness of a view of the Japan Nuclear Fuel Co. on cesium residual content and the radioactivity measurement precision regarding the molten solidified (with lowered inorganic salt used) radioactive wastes which were produced from Japan Atomic Power Company Tokai and Tokai No. 2 Power Stations. Based on the written performance report from the request and past disposal confirmation experience, a view of the JNFC is confirmed as appropriate that setting of 15% cesium residual ratio for molten solidified with volume ratio larger than 4% and less than 10% cases. (S. Ohno)

  4. Effect of compound field on horizontal continuous casting of Al-1wt.%Si alloy

    OpenAIRE

    Zhong-tao Zhang; Hong-yun Yue; Jian Zhang

    2015-01-01

    A travelling magnetic field, a power ultrasonic field, and a compound field were used separately during the horizontal continuous casting process of Al-1wt.%Si alloy. The samples obtained were characterized using an optical microscope, a scanning electron microscope, a tensile testing machine, and an electron probe microscopic analyzer to test the microstructures, properties, and element distribution of the samples. The results show that the application of a single field can enhance the mecha...

  5. Sawtooth control by on-axis electron cyclotron current drive on the WT-3 tokamak

    International Nuclear Information System (INIS)

    Asakawa, M.; Tanabe, K.; Nakayama, A.; Watanabe, M.; Nakamura, M.; Tanaka, H.; Maekawa, T.; Terumichi, Y.

    1999-01-01

    The experiments on control of sawtooth oscillations (STO) by electron cyclotron current drive (ECCD) have been performed on the WT-3 tokamak. Stabilization and excitation of STO are observed for counter-ECCD and co-ECCD, respectively, when the position of the power deposition is located inside the inversion radius. These results are due to the modification of the current profile near the magnetic axis. (author)

  6. A Project Assessment of Stabilizing System of WT Generation using Rechargeable Battery

    Science.gov (United States)

    Kojima, Yasuhiro; Takano, Tomihiro; Tanikawa, Ryoichi; Takagi, Tetsuro; Hirooka, Koutaro; Kumagai, Sadatoshi

    The expansion of the renewable energy introduction is examined as measures for controlling global warming. Wind power generation is expected as effective power resource, but the negative impact from the difficulty of an unstable output is concerned. In recent years, WT generation with contract of cut-of with shorting adjusting power and with rechargeable battery for stabilizing control are examined, but the introduction has not been accelerated yet because there is an influence in WT generation entrepreneur's business. In this paper, we make a brief summary of relation between the fluctuation of wind power generation and stability of electric power operation, and two types of approach; cut-off contract and stabilization using rechargeable battery. For the stabilization using battery, there are two methods, one is reduction control and the other is constant control. We propose a new control method for constant control based on profit optimization considering WT generation forecast and its risk of deviation. We also propose the estimation method for the .limitation of battery installation. Simulation results show the efficiency of our proposed methods.

  7. Low temperature bainite in steel with 0.26 wt% C

    Energy Technology Data Exchange (ETDEWEB)

    Soliman, Mohamed, E-mail: mohamed.soliman@tu-clausthal.de [Institute of Metallurgy, Clausthal University of Technology, D38678 Clausthal-Zellerfeld (Germany); Mostafa, Hanaa [Institute of Metallurgy, Clausthal University of Technology, D38678 Clausthal-Zellerfeld (Germany); El-Sabbagh, Ahmed S. [Faculty of Engineering, Ain-Shams University, Cairo (Egypt); Palkowski, Heinz [Institute of Metallurgy, Clausthal University of Technology, D38678 Clausthal-Zellerfeld (Germany)

    2010-11-15

    Research highlights: {yields} Low temperature bainite is produced in 0.26 wt% C steel. {yields} Alloy and process design enable decreasing the carbon content of the alloy. {yields} Generations of bainite are formed at temperatures lower than M{sub S} of the bulk alloy. {yields} Bainite plate thicknesses record values between 90 nm and 164 nm. {yields} Y.S. up to 1570 MPa and U.S. up to 2200 MPa are recorded in compression. - Abstract: Low temperature bainite has been produced in steel with 0.26 wt% C. In this steel the bainite transformation was suppressed, firstly, by adding substitutional solute of about 2 wt% Ni and, secondly, by modifying the conventional single-step bainite transformation. This modification made use of the suppression of martensite start of the undecomposed austenite due to carbon partitioning between that austenite and the formed bainitic ferrite. Consequently, it has been experimentally proved that generations of bainite were formed at temperatures lower than the martensite start of the bulk alloy. Dilatometric measurements were used to design and monitor the bainitic transformation process. The structure was characterized using light optical microscopy, scanning electron microscopy and X-ray diffractometry. In order to investigate the effect of the microstructure parameters on the material's mechanical properties, compression tests have been conducted at room temperature. The results were compared to those obtained by bainitic transformation in single-step process.

  8. Low temperature bainite in steel with 0.26 wt% C

    International Nuclear Information System (INIS)

    Soliman, Mohamed; Mostafa, Hanaa; El-Sabbagh, Ahmed S.; Palkowski, Heinz

    2010-01-01

    Research highlights: → Low temperature bainite is produced in 0.26 wt% C steel. → Alloy and process design enable decreasing the carbon content of the alloy. → Generations of bainite are formed at temperatures lower than M S of the bulk alloy. → Bainite plate thicknesses record values between 90 nm and 164 nm. → Y.S. up to 1570 MPa and U.S. up to 2200 MPa are recorded in compression. - Abstract: Low temperature bainite has been produced in steel with 0.26 wt% C. In this steel the bainite transformation was suppressed, firstly, by adding substitutional solute of about 2 wt% Ni and, secondly, by modifying the conventional single-step bainite transformation. This modification made use of the suppression of martensite start of the undecomposed austenite due to carbon partitioning between that austenite and the formed bainitic ferrite. Consequently, it has been experimentally proved that generations of bainite were formed at temperatures lower than the martensite start of the bulk alloy. Dilatometric measurements were used to design and monitor the bainitic transformation process. The structure was characterized using light optical microscopy, scanning electron microscopy and X-ray diffractometry. In order to investigate the effect of the microstructure parameters on the material's mechanical properties, compression tests have been conducted at room temperature. The results were compared to those obtained by bainitic transformation in single-step process.

  9. Coextrusion of 60 to 80 wt % U3O8 nuclear fuel elements

    International Nuclear Information System (INIS)

    Peacock, H.B.

    1980-01-01

    Aluminum-clad billets with up to 80 wt % U 3 O 8 in U 3 O 8 -Al cores have been coextruded at SRP. However, above 70 wt % U 3 O 8 , yields are low because of core-cracking. Proper selection of materials and extrusion parameters will give process conditions for successful fabrication. Studies were begun of the effects of these parameters on the flow of metal during coextrusion. In coextruded tubes, cracks are formed in large uranium oxide particles. Cracking is caused by the high tensile deformation of these particles that occurs as the cermet material flows through the die. Lower extrusion ratios and larger die angles appear to reduce severe particle cracking and increase fabrication yields. The particle size distribution of the ceramic fuel phase also influences fabricability. Six P/M assemblies with up to 57 wt % U 3 O 8 in U 3 O 8 -Al cores were successfully irradiated to 1.6 x 10 21 fissions per cm 3 of core. No swelling or blistering of the tubes occurred

  10. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    International Nuclear Information System (INIS)

    Prosviryakov, A.S.; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-01

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al 3 Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al 3 Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al 3 Zr crystals were completely dissolved in Al after 20 h. •Cubic Al 3 Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  11. Mechanical properties of hot-pressed Al-4.5 wt. % Cu/WC composite

    Directory of Open Access Journals (Sweden)

    Samaneh Bernoosi

    2014-12-01

    Full Text Available In this study, the elemental powders of aluminum and copper were initially subjected to mechanical alloying using an attrition ball mill under argon atmosphere to produce an Al-4.5 wt% Cu powder alloy. The WC nanoparticles were then added to the powder alloy and milled in a planetary ball mill to explore the role of the WC nanoparticles on the mechanical properties of the fabricated composite powder. The experimental results revealed that a solid solution of Al-Cu could be formed after MA and a good dispersion of the WC nanoparticles in the aluminum matrix was obtained as characterized using X-ray diffraction and scanning electron microscopy, respectively. The results of hardness and compression tests of the hot pressed composites indicated that the MA followed by the hot-press processes was successful to fabricate an alloy and a metal matrix composite with considerable mechanical properties. However, a decreasing trend in the hardness and strength of the composites with the WC contents of more than 5wt% was observed. The maximum values of 260 HV and 575 MPa were obtained for a composite containing 5 wt% of nano ceramic particles.

  12. HRTEM characterization of melt-spun Al-Si-Cu-Mg alloys solidified at different rates

    International Nuclear Information System (INIS)

    Alfonso, Ismeli; Maldonado, Cuauhtemoc; Medina, Ariosto; Gonzalez, Gonzalo; Bejar, Luis

    2006-01-01

    Six quaternary alloys Al-6Si-3Cu-xMg (x = 0.59, 3.80 and 6.78 wt.%) were produced by melt spinning using two different tangential speeds of the copper wheel (30 and 45 ms -1 ), and characterized using optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and microhardness. At 30 ms -1 , XRD and TEM investigations revealed the presence of Al 2 Cu (θ) for the alloy with 0.59%Mg and Al 5 Cu 2 Mg 8 Si 6 (Q) for the alloys with 3.80 and 6.78%Mg. The increase in microhardness of the alloys with higher Mg content is attributed to the presence of nanosized a-Al particles and a higher content of Q nanoparticles. At 45 ms -1 the alloying element content in solid solution is increased due to the fact that the quantity of free second phases (θ and Q nanoparticles) has decreased. For this rotation speed, amorphous regions of α -Al were observed, increasing microhardness compared to the 30 ms -1 ribbons

  13. A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat` l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

    1998-12-31

    A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

  14. A coupled analysis of fluid flow, heat transfer and deformation behavior of solidifying shell in continuously cast beam blank

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Eui; Yeo, Tae Jung; Oh, Kyu Hwan; Yoon, Jong Kyu [School of Materials Science and Engineering, Seoul Nat`l Univ., Seoul (Korea, Republic of); Han, Heung Nam [Oxford Center for Advanced Materials and Composites, Department of Materials, Univ. of Oxford (United Kingdom)

    1997-12-31

    A mathematical model for a coupled analysis of fluid flow, heat transfer and deformation behavior in the continuously cast beam blank has been developed. The fluid flow, heat transfer and solidification in the mold region were analyzed with 3-dimensional finite difference method (FDM) based on control volume method. A body fitted coordinate system was introduced for the complex geometry of the beam blank. The effects of turbulence and natural convection of molten steel were taken into account in determining the fluid flow in the strand. The thermo-elasto-plastic deformation behavior in the cast strand and the formation of air gap between the solidifying shell and the mold were analyzed by the finite element method (FEM) using the 2-dimensional slice temperature profile calculated by the FDM. The heat flow between the strand and the mold was evaluated by the coupled analysis between the fluid flow-heat transfer analysis and the thermo-elasto-plastic stress analysis. In order to determine the solid fraction in the mushy zone, the microsegregation of solute element was assessed. The effects of fluid flow on the heat transfer, the solidification of steel and the distribution of shell thickness during the casting of the beam blank were simulated. The deformation behavior of the solidifying shell and the possibility of cracking of the strand were also investigated. The recirculating flows were developed in the regions of the web and the flange tip. The impinging of the inlet flow from the nozzle retarded the growing of solidifying shell in the regions of the fillet and the flange. The air gap between the strand and the mold was formed near the region of the corner of the flange tip. At the initial stage of casting, the probability of the surface cracking was high in the regions of the fillet and the flange tip. After the middle stage of casting, the internal cracking was predicted in the regions of the flange tip, and between the fillet and the flange tip. (author) 38

  15. Frequency of WT1 and 11p15 constitutional aberrations and phenotypic correlation in childhood Wilms tumour patients

    NARCIS (Netherlands)

    Segers, H.; Kersseboom, R.; Alders, M.; Pieters, R.; Wagner, A.; van den Heuvel-Eibrink, M. M.

    2012-01-01

    Introduction: In 9-17% of Wilms tumour patients a predisposing syndrome is present, in particular WT1-associated syndromes and overgrowth syndromes. Constitutional WT1 mutations or epigenetic changes on chromosome 11p15 have also been described in Wilms tumour patients without phenotypic

  16. Prediction of as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal conditions

    International Nuclear Information System (INIS)

    Du, Qiang; Li, Yanjun

    2015-01-01

    In this paper, a multi-scale as-cast grain size prediction model is proposed to predict as-cast grain size of inoculated aluminum alloys melt solidified under non-isothermal condition, i.e., the existence of temperature gradient. Given melt composition, inoculation and heat extraction boundary conditions, the model is able to predict maximum nucleation undercooling, cooling curve, primary phase solidification path and final as-cast grain size of binary alloys. The proposed model has been applied to two Al-Mg alloys, and comparison with laboratory and industrial solidification experimental results have been carried out. The preliminary conclusion is that the proposed model is a promising suitable microscopic model used within the multi-scale casting simulation modelling framework. (paper)

  17. Morphological variants of carbides of solidification origin in the rapidly solidified powder particles of hypereutectic iron alloy

    International Nuclear Information System (INIS)

    Kusy, M.; Grgac, P.; Behulova, M.; Vyrostkova, A.; Miglierini, M.

    2004-01-01

    The paper deals with the analysis of the morphological variants of solidification microstructures and vanadium rich M 4 C 3 carbide phases in the rapidly solidified (RS) powder particles from hypereutectic Fe-C-Cr-V alloy prepared by the nitrogen gas atomisation. Five main types of solidification microstructures were identified in RS particles: microstructure with globular carbides, microstructure with globular and star-like carbides, microstructure with primary carbides in the centres of eutectic colonies, microstructure with eutectic colonies without primary carbides and microstructure with eutectic spherulites. Based on the morphological features of carbide phases and the thermal history of RS particles, the microstructures were divided into two groups - microstructures morphologically affected and non-affected during the post-recalescence period of solidification. Thermophysical reasons for the morphologically different M 4 C 3 carbide phases development in the RS powder particles are discussed

  18. Effect of processing on the microstructural development in a rapidly solidified Al-Fe-V-Si alloy

    International Nuclear Information System (INIS)

    Srivastava, A.K.; Ranganathan, S.; Ojha, S.N.

    1993-01-01

    An Al 80 Fe 10 Si 6 alloy has been rapidly solidified using melt spinning, gas atomization and spray forming processes. The effect of processing techniques on the microstructural characteristics of the alloy has ben evaluated. The melt spun alloy has shown an icosahedral quasicrystalline phase surrounded by a rational approximant structure of the icosahedral phase. The rational approximant structure has been identified as a crystalline cubic silicide phase. The atomized powders have exhibited cellular and dendritic morphology depending on the size of particles. In addition, the second phase particles of the silicide phase are observed to decorate the cell boundaries and interdendritic regions. In contrast, the alloy processed by spray deposition has revealed an equiaxed solidification morphology with a uniform dispersion of find silicon phase inside the grain. The origin of the microstructure in the alloy processed by these techniques is discussed. The results are compared wherever possible with the commercially available Al-Fe-V-Si alloys

  19. Tensile behavior change depending on the microstructure of a Fe-Cu alloy produced from rapidly solidified powder

    International Nuclear Information System (INIS)

    Kakisawa, Hideki; Minagawa, Kazumi; Halada, Kohmei

    2003-01-01

    The relationship between consolidating temperature and the tensile behavior of iron alloy produced from Fe-Cu rapidly solidified powder is investigated. Fe-Cu powder fabricated by high-pressure water atomization was consolidated by heavy rolling at 873-1273 K. Microstructural changes were observed and tensile behavior was examined. Tensile behavior varies as the consolidating temperature changes, and these temperature-dependent differences depend on the morphology of the microstructure on the order of micrometers. The sample consolidated at 873 K shows a good strength/elongation balance because the powder microstructure and primary powder boundaries are maintained. The samples consolidated at the higher temperatures have a microstructure of recrystallized grains, and these recrystallized samples show the conventional relationship between tensile behavior and grain size in ordinal bulk materials

  20. Hydration products and mechanical properties of hydroceramics solidified waste for simulated Non-alpha low and intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Wang Jin; Hong Ming; Wang Junxia; Li Yuxiang; Teng Yuancheng; Wu Xiuling

    2011-01-01

    In this paper, simulated non-alpha low and intermediate level radioactive wastes was handled as curing object and that of 'alkali-slag-coal fly ash-metakaolin' hydroceramics waste forms were prepared by hydrothermal synthesis method. The hydration products were analyzed by X ray diffraction. The composition of hydrates and the compressive strength of waste forms were determined and measured. The results indicate that the main crystalline phase of hydration products were analcite when the temperature was 150 to 180 degree C and the salt content ratio was 0.10 to 0.30. Analcite diffraction peaks in hydration products is increasing when the temperature was raised and the reaction time prolonged. Strength test results show that the solidified waste forms have superior compressive strength. The compressive strength gradually decreased with the increase in salt content ratio in waste forms. (authors)

  1. Characterization of solidified radioactive wastes produced at Montalto di Castro BWR plant with reference to the site storage

    International Nuclear Information System (INIS)

    Donato, A.; Ricci, G.; Pace, A.

    1985-01-01

    The cement solidification of the Montalto di Castro BWR plant radwastes has been studied both from the point of view of the mixtures of formulation and of the product characterization. Five radwaste types and mixtures of them have been taken into consideration, determining the best chemical formulations starting from the compressive strenght as leading parameter. The solidified products have been characterized from the point of view of the freeze and thawing resistance, the water immersion resistance, the leachability, the dimensional changes and the free standing water. All the tests have been performed taking into account the real site conditions, so the leaching tests and the water immersion tests have been carried out using sea water and table water as leachant

  2. Shipment and Disposal of Solidified Organic Waste (Waste Type IV) to the Waste Isolation Pilot Plant (WIPP)

    International Nuclear Information System (INIS)

    D'Amico, E. L; Edmiston, D. R.; O'Leary, G. A.; Rivera, M. A.; Steward, D. M.

    2006-01-01

    In April of 2005, the last shipment of transuranic (TRU) waste from the Rocky Flats Environmental Technology Site to the WIPP was completed. With the completion of this shipment, all transuranic waste generated and stored at Rocky Flats was successfully removed from the site and shipped to and disposed of at the WIPP. Some of the last waste to be shipped and disposed of at the WIPP was waste consisting of solidified organic liquids that is identified as Waste Type IV in the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC) document. Waste Type IV waste typically has a composition, and associated characteristics, that make it significantly more difficult to ship and dispose of than other Waste Types, especially with respect to gas generation. This paper provides an overview of the experience gained at Rocky Flats for management, transportation and disposal of Type IV waste at WIPP, particularly with respect to gas generation testing. (authors)

  3. Segregation and microstructure evolution in chill cast and directionally solidified Ni-Mn-Sn metamagnetic shape memory alloys

    Science.gov (United States)

    Czaja, P.; Wierzbicka-Miernik, A.; Rogal, Ł.

    2018-06-01

    A multiphase solidification behaviour is confirmed for a range of Ni-rich and Ni-deficient Ni-Mn-Sn induction cast and directionally solidified (Bridgman) alloys. The composition variation is primarily linked to the changing Mn/Sn ratio, whereas the content of Ni remains largely stable. The partitioning coefficients for the Ni50Mn37Sn13 and Ni46Mn41.5Sn12.5 Bridgman alloys were obtained according to the Scheil equation based on the composition distribution along the longitudinal cross section of the ingots. Homogenization heat treatment performed for 72 h at 1220 K turned out sufficient for ensuring chemical uniformity on the macro- and microscale. It is owed to a limited segregation length scale due to slow cooling rates adopted for the directional solidification process.

  4. A study on crystalline phases present in the as-solidified and crystallized microstructures in Zr53Cu21Al10Ni8Ti8 alloy

    International Nuclear Information System (INIS)

    Neogy, S.; Tewari, R.; Srivastava, D.; Dey, G.K.

    2011-01-01

    In the present study the as-solidified and crystallized microstructures of Zr 53 Cu 21 Al 10 Ni 8 Ti 8 alloy have been examined in detail. Solidification was carried out by melt spinning, suction casting and copper mould casting techniques. The last technique yielded a partially crystalline microstructure, whereas, the other two techniques resulted in amorphous microstructures. (author)

  5. Analysis of Light Gathering Abilities of Dynamically Solidified Micro-lenses, and Their Implementation to Improve Sensitivity of Fluorescent PCR Micro-detectors.

    Science.gov (United States)

    Wu, Jian; Guo, Wei; Wang, Chunyan; Yu, Kuanxin; Chen, Tao; Li, Yinghui

    2015-06-01

    Fluorescent polymerase chain reaction (PCR) is becoming the preferred method of quantitative analysis due to its high specificity and sensitivity. We propose to use a new kind of micro-lens, dynamically solidified with optic glue, to improve the sensitivity of fluorescent PCR micro-detector. We developed light ray track equations for these lenses and used them to calculate relative light intensity distribution curve for stimulation lenses and illumination point probability distribution curve for detection lenses. We manufactured dynamically solidified micro-lenses using optic glue NOA61, and measured their light gathering ability. Lenses with radius/thickness (R/H) ratio of 4 reached light focusing ratio of 3.85 (stimulation lens) and photon collection efficiency of 0.86 (detection lens). We then used dynamically solidified lenses in PCR fluorescence micro-detector and analyzed their effect on the detector sensitivity. We showed that the use of dynamically solidified micro-lenses with R/H = 4 resulted in over 4.4-fold increased sensitivity of the detector.

  6. Experimental study on the properties of drum-packed, cement solidified waste package of pre and after sea dumping test of sea depth 30m and 100m

    International Nuclear Information System (INIS)

    Maki, Yasuro; Abe, Hirotoshi; Hattori, Seiichi

    1976-01-01

    Japan Marine Science and Technology Center has been tackling with the development of the monitoring system to confirm the soundness of drum-packed, cement-solidified low level radioactive waste (the package) during falling and after reaching at sea bed when it is dumped into sea. The test was carried out at Sagami Bay of 30 m and 100 m sea depth using non-radioactive packages. The observation of the falling behaviour of packages in sea was carried out by taking photographs of the motion of packages with an underwater 16 mm movie camera and an underwater industrial TV (ITV), and the observation of the soundness and the area of packages scattered on sea bed was carried out with an underwater ITV and an underwater 70 mm snap camera which were set up on the frame. The proportion of cement-solidified waste was decided so that the uni-axial compressive strength of the cement-solidified waste satisfies the condition of ''The tentative guideline''. Prior to tests at sea, hydrostatic pressure test of packages are carried out on land. After that, core specimens were sampled to obtain the uniaxial compressive strength from packages and were tested. After sea dumping tests, 6 packages were recovered from sea bed, and the soundness were tested. As the results, the deformation and damage of drums and cement solidified waste packages did not occur at all. (Kako, I.)

  7. The study of microplasticity mechanism in Ti-50 wt.%Nb alloy with high hydrogen content

    International Nuclear Information System (INIS)

    Golovin, I.S.; Kollerov, M.U.; Schinaeva, E.V.

    1996-01-01

    The upper yield point (∼ 700 MPa) appears at the compression test curves (ε=0.024 sec -1 ) of b.c.c. Nb-50 wt.%Ti due to the increase of hydrogen content from 0 to 0.2 wt.% and more and leads to the non monotonous increase in compressive lower yield stress from 400 to 550 MPa. Taking into account close connection between macro- and microplasticity of metallic materials the low frequency (∼ 2 Hz) amplitude dependent internal friction (ADIF) spectrum (γ = 1. 60.10 -5 ) in hydrogenized Nb-50 wt.% Ti and Nb samples are studied. The ADIF investigation of the closed hysteresis loop ''loading-unloading'' shows the dependence of its width from the hydrogen content which evidences the fact of dislocation unpinning from hydrogen atmospheres in the 1/2 cycle of loading. The study of ADIF spectrum for samples with different hydrogen content before and after torsion deformation (γ ∼ 2%) shows the sharp increase of IF level at γ = 1. 10.10 -5 after ∼1 hour of natural ageing. At that time the ADIF curves change its shape from Γ-shape to U-shape. The amplitude range of the IF increase depends on the hydrogen content. It is the interaction of hydrogen atoms with dislocations that caused the above mentioned effect which has not been observed in hydrogen free samples. The time estimation for the formation of thermodynamically stable hydrogen atmospheres on dislocations shows that hydrogen atmospheres could not follow the dislocation during compressive tests and that leads to the upper yield point appearance. (orig.)

  8. Structure and phase stability of a Pu-0.32 wt% Ga alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, D.W., E-mail: David.Wheeler@awe.co.uk; Ennaceur, S.M.; Matthews, M.B.; Roussel, P.; Bayer, P.D.

    2016-08-01

    In plutonium-gallium (Pu-Ga) alloys that have a Ga content of 0.3–0.4 wt%, their readiness to transform to α′ renders them of particular interest in efforts to understand the tenuous nature of δ phase stability. The present study is a comprehensive examination of the structure and phase stability of a cast Pu-0.32 wt% Ga alloy, the Ga content being close to the minimum amount needed to retain the δ phase to ambient temperature. The alloy was characterised in both the as-cast condition as well as following a homogenising heat treatment. The 250-h heat treatment at 450 °C was shown to achieve an apparently stable δ-Pu phase. However, the stability of the δ-Pu phase was shown to be marginal: partial transformation to α′-Pu was observed when the alloy was subjected to hydrostatic compression. Similar transformation was also apparent during metallographic preparation as well as during hardness indentation. The results provide new understanding of the nature of δ phase stability. - Highlights: • New insights into the delta phase stability of a Pu-0.32 wt% Ga alloy. • Density and DSC of as-cast alloy both show α-Pu contents of approximately 30%. • The heat-treated alloy has a largely δ-Pu structure at ambient temperature. • Heat-treated alloy susceptible to δ → α transformation during hardness indentation.

  9. Densification, phase stability and in vitro biocompatibility property of hydroxyapatite-10 wt% silver composites.

    Science.gov (United States)

    Nath, Shekhar; Kalmodia, Sushma; Basu, Bikramjit

    2010-04-01

    In this paper, we demonstrate how a simple fabrication route, i.e., pressureless sintering of mechanically mixed powders can be employed to develop hydroxyapatite (HAp, Ca(10)(PO(4))(6)(OH)(2))-silver (Ag) bioceramic composites with superior combination of physical (hardness, toughness), non-cytotoxicity, cytocompatiblity and anti-microbial property. The densification results show that such composites can be sintered at 1200 degrees C for 2 h near to theoretical density (>98% rho(th).) An important observation is that the dissociation of HAp phase can be prevented during sintering up to 1300 degrees C for 2 h in HAp-10 wt% Ag composites. The stability of HAp in presence of silver is discussed in reference to the results obtained using XRD, FTIR and Raman spectroscopy. The hardness values of the composites are comparable (approximately 6.5 GPa) to that of pure HAp, despite of the presence of softer Ag particles. The sintered composites exhibit modest crack growth resistance property and their toughness varies in the range of 0.9-1.2 MPa m(0.5), depending on sintering temperature. For selected samples, the in vitro characterization was performed using mouse fibroblast (L929) and human osteosarcoma (MG63) cell lines. The combination of biochemical assays (MTT, ALP and osteocalcin) confirm that HAp-10 wt% Ag biocomposites have comparable or even better cellular viability, osteogenic differentiation and bone mineralization as well as osteoinduction property. Antibacterial experiments involving gram-negative bacteria, Escherichia coli confirm excellent bactericidal property of HAp-10 wt% Ag composites, sintered using mechanically mixed powders.

  10. Investigation of nanostructured Al-10 wt.% Zr material prepared by ball milling for high temperature applications

    Energy Technology Data Exchange (ETDEWEB)

    Prosviryakov, A.S., E-mail: pro.alex@mail.ru; Shcherbachev, K.D.; Tabachkova, N.Yu.

    2017-01-15

    Ground chips of as-cast Al-10 wt.% Zr alloy were subjected to mechanical alloying (MA) with 5 vol.% of nanodiamond addition in a high energy planetary ball-mill. The aim of this work was to investigate the microstructure, phase transformation and mechanical properties of the material both after MA and after subsequent annealing. Optical and transmission electron microscopes were used for morphological and microstructural analysis. The effect of milling time on powder microhardness, Al lattice parameter, lattice microstrain and crystallite size was determined. It was shown that mechanical alloying of as-cast Al-10wt.%Zr alloy during 20 h leads to a complete dissolution of the primary tetragonal Al{sub 3}Zr crystals in aluminum. At the same time, the powder microhardness increases to 370 HV. Metastable cubic Al{sub 3}Zr phase nanoparticles precipitate from the Al solution due to its decomposition after annealing, however, the Al solid solution remains supersaturated and nanocrystalline. Compression tests at room temperature and at 300 °C showed that the strength values of the hot-pressed samples reach 822 MPa and 344 MPa, respectively. - Highlights: •As-cast Al-10 wt.% Zr alloy was mechanically alloyed with 5 vol.% nanodiamond. •The primary tetragonal Al{sub 3}Zr crystals were completely dissolved in Al after 20 h. •Cubic Al{sub 3}Zr phase nanoparticles precipitated from Al solution after aging. •The aged bulk material showed a high strength at room and elevated temperatures.

  11. Mechanical alloying of Cu-xCr (x = 3, 5 and 8 wt.%) alloys

    International Nuclear Information System (INIS)

    Aguilar, C.; Ordonez, S.; Guzman, D.; Rojas, P.A.

    2010-01-01

    This work studies the structural evolution of Cu-xCr (x = 3, 5 and 8 wt.%) alloys processed by mechanical alloying using X-ray diffraction profiles, scanning microscopy and microhardness analysis. X-ray diffraction analysis using the modified Williamson-Hall and Warren-Averbach methods were used to determine structural properties, such as crystallite size, stacking fault probability and energy, dislocation density, lattice parameters and crystallite size distribution of metallic powder as a function of Cr amount and milling time. Lattice defects increase the Gibbs free energy and the Gibbs free energy curves shift upward, therefore the solubility limit change.

  12. Reaction layer in U-7WT%MO/Al diffusion couples

    International Nuclear Information System (INIS)

    Mirandou, M.I.; Balart, S.N.; Ortiz, M.; Granovsky, M.S.

    2003-01-01

    New results of the reaction layer characterization between γ (U-7wt%Mo) alloy and Al, in chemical diffusion couples, are presented. The analysis was performed using optical and scanning electron microscopy with EDAX and X-ray diffraction techniques. Besides the main components (U, Mo)Al 3 and (U, Mo)Al 4 , already reported, two ternary compounds of high Al content have been identified in the reaction layer when it grew in retained or decomposed γ (U, Mo) phase, respectively. The drastic consequence on the interdiffusion behavior due to the thermal instability of the retained γ (U, Mo) phase is discussed. (author)

  13. Radiation-enhanced precipitation in a V-10 wt % Ti alloy

    International Nuclear Information System (INIS)

    Agarwal, S.C.; Taylor, A.

    1976-01-01

    A V-10 wt % Ti alloy was irradiated with 2.7 MeV 51 V + at 650 0 C to doses of 2 to 60 dpa. No void swelling was observed at any dose. The irradiation resulted in an enhancement of a precipitation process similar to that observed in unirradiated materials. The precipitates in irradiated specimens were found to have the NaCl-type cubic crystal structure with a lattice parameter of TiO. The orientation relationship between the matrix and the precipitates was the same as that observed under thermal equilibrium conditions in unirradiated materials

  14. Microanalysis on the Hydrogen Ion Irradiated 50 wt pct TiC-C Films

    Institute of Scientific and Technical Information of China (English)

    Hui JIANG; Yaoguang LIU; Ningkang HUANG

    2007-01-01

    The 50 wt pct TiC-C films were prepared on stainless steel substrates by using a technique of ion beam mixing.These films were irradiated by hydrogen ion beam with a dose of 1×1018 ions/cm2 and an energy of 5 keV.Microanalysis of X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS) were used to analyze the films before and after hydrogen ion irradiation and to study the mechanism of hydrogen resistance.

  15. Long-term oxidation of Zr-2.5 wt% Nb alloy

    International Nuclear Information System (INIS)

    Cox, B.

    1976-09-01

    A long-term study of the oxidation of Zr-2.5 wt% Nb alloys in water, steam, air and fused nitrate/nitrite salt has been carried out as a function of material batch, degree of cold-work, and heat treatment. Examination after oxidation was by weight gain, optical microscopy, replica electron microscopy, scanning electron microscopy, oxide impedance measurements, mercury porosimetry and metallographic sectioning. The results are compared with other published work and some hypothetical oxidation mechanisms are proposed and discussed. (author)

  16. Analysis on Radioactive Waste Transmutation in Light Water cooled Hyb-WT

    International Nuclear Information System (INIS)

    Hong, Seonghee; Kim, Myung Hyun

    2014-01-01

    A feasibility of realization is much higher in FFHR compared with pure fusion. A combination of plasma fusion source for neutrons with a subcritical reactor at the blanket side has much higher capability in transmutation of waste as well as reactor safety compared with fission reactor options. Fusion-Fission Hybrid Reactor (FFHR) uses various coolants depending on the purpose. It is important that coolant being used should be suitable to reactor purpose, because reactor performance and the design constraints may change depending on the coolant. There are basically two major groups of coolants for FFHR. One group of coolant does not contain Li. They are Na, Pb-Bi, H 2 O and D 2 O. The other group contains Li for tritium breeding. They are Li, LiPb, LiSN, FLIBE and FLiNaBe. Currently, the issue in FFHR is its implication for radioactive waste transmutation (FFHR for WT). Because radioactive wastes of spent nuclear fuel (SNF) are transmuted using fusion neutron source. Therefore a suitable coolant should be used for effective waste transmutation. . In FFHR for WT, LiPb coolant is being used mainly because of tritium production in Li and high neutron economic through reaction in Pb. However different coolants use such as Na, Pb-Bi are used in fast reactors and accelerator driven systems (ADS) having same purpose. In this study, radioactive waste transmutation performance of various coolants mentioned above will be compared and analyzed. Through this study, the coolants are judged primarily for their support to waste transmutation disregarding their limitation to reactor design and tritium breeding capability. First, performance of the light water coolant regarding radioactive waste transmutation was analyzed among various coolants mentioned above. In this paper, performance of radioactive waste transmutation can be known depending on different volume fractions (54.53, 60.27, 97.94vol.%) of the light water. Light water dose required fusion power lower than LiPb due to

  17. Ammonium nitrate with 15 wt % potassium nitrate-ethylenediamine dinitrate-nitroguanidine system

    Energy Technology Data Exchange (ETDEWEB)

    Spencer, W.; Cady, H.H.

    1981-01-01

    The phase diagram for the ternary system ammonium nitrate(AN) with 15 wt % potassium nitrate(AN:15KN)-ethylenediamine dinitrate(EDD)-nitroguanidine(NQ) has been determined from room temperature to the melting point. The ternary eutectic temperature, measured for a mixture containing 67.24, 25.30, and 7.46 mole % of AN:15KN, EDD, and NQ, respectively, was found to be 98.9/sup 0/C. The binary phase diagrams for the systems AN:15KN-EDD, AN:15KN-NQ, and EDD-NQ were also determined.

  18. Environmental impact assessment of a WtE plant after structural upgrade measures.

    Science.gov (United States)

    Passarini, Fabrizio; Nicoletti, Monica; Ciacci, Luca; Vassura, Ivano; Morselli, Luciano

    2014-04-01

    The study focuses on analysing the evolution of environmental impacts caused by a medium-large Italian WtE plant before and after revamping and maintenance operations, with the aim of providing an evaluation of how much these structural upgrade measures may affect the total environmental performance. LCA methodology was applied for the modelling and comparison of six WtE scenarios, each describing the main structural upgrades carried out in the plant over the years 1996-2011. The comparison was conducted by adopting 1ton of MSW as the functional unit, and the net contribution from energy recovery to power generation was distinguished by defining consistent national grid electricity mixes for every year considered. The Ecoindicator99 2.09 impact assessment method was used to evaluate the contribution to midpoint and endpoint categories (e.g. carcinogens, respiratory inorganics and organics, climate change, damage to human health). Lastly, the "Pedigree quality matrix" was applied to verify the reliability and robustness of the model created. As expected, the results showed better environmental scores after both the implementation of new procedures and the integration of operations. However, while a net reduction of air emissions seems to be achievable through dedicated flue gas treatment technologies, outcomes underscored potentials for improving the management of bottom ash through the adoption of alternative options aimed to use that solid residue mainly as filler, and to decrease risks from its current disposal in landfill. If the same effort that is put into flue gas treatment were devoted to energy recovery, the targets for the WtE plant could be easily met, achieving a higher sustainability. This aspect is even more complex: national policies for implementing greener and renewable energy sources would result in a lower impact of the national energy mix and, hence, in a lower net avoided burden from energy recovery. The study confirmed the expected improvements

  19. Study on the sintered characteristics and properties of nanostructured WC–15 wt% (Fe–Ni–Co) and WC–15 wt% Co hard metal alloys

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Shih-Hsien, E-mail: changsh@ntut.edu.tw [Department of Materials and Mineral Resources Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Chang, Ming-Hung [Department of Materials and Mineral Resources Engineering, National Taipei University of Technology, Taipei 10608, Taiwan (China); Huang, Kuo-Tsung [Department of Auto-Mechanics, National Kangshan Agricultural Industrial Senior High School, Kaohsiung 82049, Taiwan (China)

    2015-11-15

    In this work, four different vacuum sintering temperatures (1250 °C, 1300 °C, 1350 °C and 1400 °C) were studied to determine the optimal process parameters of nano WC–15 wt% (Fe–Ni–Co) and WC–15 wt% Co sintered hard metal alloys. Experimental results showed that the optimal sintering temperatures for nano WC–(Fe–Ni–Co) and WC–Co alloys were 1300 °C and 1350 °C for 1 h, respectively. The sintered nano WC–(Fe–Ni–Co) and WC–Co hard metal alloys showed a good contiguity of 0.44 and 0.42; hardness was enhanced to HRA 90.83 and 90.92; the transverse rupture strength (TRS) increased to 2567.97 and 2860.08 MPa; and K{sub IC} was 16.23 and 12.33 MPa√m, respectively. Although the nano WC–(Fe–Ni–Co) alloys possessed a slightly lower TRS value, they exhibited superior fracture toughness (K{sub IC}) and hardness similar to that of the nano WC–Co material. Significantly, nano WC–(Fe–Ni–Co) alloys could be sintered at a lower temperature and still retained their excellent mechanical properties. - Graphical abstract: The following figure shows the fracture morphology of the WC–(Fe–Ni–Co) and WC–Co specimens by means of high-magnification SEM after the K{sub IC} tests. Fig. a shows that numerous binder phases (Fe–Ni–Co) existed in the crack areas, which resisted the penetration and extension of the cracks. Due to the bridging effect of the binder phase, the stress concentration of the crack tip will be resolved through plastic deformation; thus, the cracks did not continue to extend. Once the deformation reaches a critical value, the crack propagation occurs. Meanwhile, the binder phase can link together the two crack faces through the bridging process. Although parts of the cracked areas also showed the bridging effect in the WC–Co specimens, as shown by the arrows (Fig. b), the crack propagation path was not obviously affected. This result corresponds to the tortuosity phenomenon. Consequently, the bridging process

  20. Thermal compatibility of U-2wt.%Mo and U-10wt.%Mo fuel prepared by centrifugal atomization for high density research reactor fuels

    International Nuclear Information System (INIS)

    Kim Ki Hwan; Lee Don Bae; Kim Chang Kyu; Kuk Il Hyun; Hofman, G.E.

    1997-01-01

    Research on the intermetallic compounds of uranium was revived in 1978 with the decision by the international research reactor community to develop proliferation-resistant fuels. The reduction of 93% 235 U (HEU) to 20% 235 U (LEU) necessitates the use of higher U-loading fuels to accommodate the addition 238 U in the LEU fuels. While the vast majority of reactors can be satisfied with U 3 Si 2 -Al dispersion fuel, several high performance reactors require high loadings of up to 8-9 g U cm -3 . Consequently, in the renewed fuel development program of the Reduced Enrichment for Research and Test Reactors (RERTR) Program, attention has shifted to high density uranium alloys. Early irradiation experiments with uranium alloys showed promise of acceptable irradiation behavior, if these alloys can be maintained in their cubic γ-U crystal structure. It has been reported that high density atomized U-Mo powders prepared by rapid cooling have metastable isotropic γ-U phase saturated with molybdenum, and good γ-U phase stability, especially in U-10wt.%Mo alloy fuel. If the alloy has good thermal compatibility with aluminium, and this metastable gamma phase can be maintained during irradiation, U-Mo alloy would be a prime candidate for dispersion fuel for research reactors. In this paper, U-2w.%Mo and U-10w.%Mo alloy powder which have high density (above 15 g-U/cm 3 ), are prepared by centrifugal atomization. The U-Mo alloy fuel meats are made into rods extruding the atomized powders. The characteristics related to the thermal compatibility of U-2w.%Mo and U-10w.%Mo alloy fuel meat at 400 o C for time up to 2000 hours are examined. (author)

  1. Effect of compound field on horizontal continuous casting of Al-1wt.%Si alloy

    Directory of Open Access Journals (Sweden)

    Zhong-tao Zhang

    2015-03-01

    Full Text Available A travelling magnetic field, a power ultrasonic field, and a compound field were used separately during the horizontal continuous casting process of Al-1wt.%Si alloy. The samples obtained were characterized using an optical microscope, a scanning electron microscope, a tensile testing machine, and an electron probe microscopic analyzer to test the microstructures, properties, and element distribution of the samples. The results show that the application of a single field can enhance the mechanical properties and reduce the segregation of Si element in Al-1wt.%Si alloy to some extent. The application of a compound field can obtain the best refinement and homogeneity of the Si element in the alloy, leading to the highest increase of tensile strength and elongation among the three applied fields. The mechanism of the action of external fields on the refinement of microstructures and homogeneity of the Si element is discussed and the compound field is considered to be an effective method to achieve high quality Al alloys.

  2. Tests of rhodamine WT dye for toxicity to oysters and fish

    Science.gov (United States)

    Parker, Garald G.

    1973-01-01

    Because of the toxicity to oyster larvae and eggs of rhodamine B dye in concentrations greater than 1 mg/l in earlier tests, there was a concern that rhodamine WT, a similar tracer dye, would have a detrimental effect on marine life being developed under the aquaculture program of the Lummi Indian Tribe near Bellingham, Wash. Tests showed that 48-hour exposures at 24° C of 11,000 oyster eggs per liter and 6,000 12-day-old larvae per liter, in sea water with concentrations of rhodamine WT ranging from 1 μg/l to 10 mg/l, resulted in development of the eggs to normal straight-hinge larvae and no abnormalities in the larvae development. Tests made on the smolt of both silver salmon and Donaldson trout, with the fish held for 17.5 hours in a tankfull of sea water with a dye concentration of 10 mg/l at 22°C showed no mortalities or respiratory problems. With the concentration increased to 375 mg/l, and the time extended an additional 3.2 hours, still no mortalities or abnormalities were noted. The fish remained healthy in dye-free water when last checked a month after the test.

  3. Characterization of the reaction layer in U-7wt%Mo/Al diffusion couples

    Energy Technology Data Exchange (ETDEWEB)

    Mirandou, M.I.; Balart, S.N.; Ortiz, M.; Granovsky, M.S. E-mail: granovsk@cnea.gov.ar

    2003-11-15

    The reaction layer in chemical diffusion couples U-7wt%Mo/Al was investigated using optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction (XRD) techniques. When the U-7wt%Mo alloy was previously homogenized and the {gamma}(U, Mo) phase was retained, the formation of (U, Mo)Al{sub 3} and (U, Mo)Al{sub 4} was observed at 580 deg. C. Also a very thin band was detected close to the Al side, the structure of the ternary compound Al{sub 20}UMo{sub 2} might be assigned to it. When the decomposition of the {gamma}(U, Mo) took place, a drastic change in the diffusion behavior was observed. In this case, XRD indicated the presence of phases with the structures of (U, Mo)Al{sub 3}, Al{sub 43}U{sub 6}Mo{sub 4}, {gamma}(U, Mo) and {alpha}(U) in the reaction layer.

  4. Susceptibility of cold-worked zirconium-2.5 wt% niobium alloy to delayed hydrogen cracking

    International Nuclear Information System (INIS)

    Coleman, C.E.

    1976-01-01

    Notched tensile specimens of cold-worked zirconium-2.5 wt% niobium alloy have been stressed at 350 K and 520 K. At 350 K, above a possible threshold stress of 200 MPa, specimens exhibited delayed failure which was attributed to hydride cracking. Metallography showed that hydrides accumulated at notches and tips of growing cracks. The time to failure appeared to be independent of hydrogen content over the range 7 to 100 ppm hydrogen. Crack growth rates of about 10 -10 m/s deduced from fractography were in the same range as those necessary to fracture pressure tubes. The asymptotic stress intensity for delayed failure, Ksub(1H), appeared to be about 5 MPa√m. With this low value of Ksub(1H) small surface flaws may propagate in pressure tubes which contain large residual stresses. Stress relieving and modified rolling procedures will reduce the residual stresses to such an extent that only flaws 12% of the wall thickness or greater will grow. At 520 K no failures were observed at times a factor of three greater than times to failure at 350 K. Zirconium-2.5 wt% niobium appears to be safe from delayed hydrogen cracking at the reactor operating temperature. (author)

  5. Evidence of amorphous interdiffusion layer in heavy ion irradiated U–8wt%Mo/Al interfaces

    International Nuclear Information System (INIS)

    Chiang, H-Y.; Zweifel, T.; Palancher, H.; Bonnin, A.; Beck, L.; Weiser, P.; Döblinger, M.; Sabathier, C.; Jungwirth, R.; Petry, W.

    2013-01-01

    U–Mo/Al based nuclear fuels are worldwide considered as the most promising high density fuel for the conversion of high flux research and test reactors from highly enriched uranium to lower enrichment. However in-pile growth of an amorphous interdiffusion layer at the U–Mo/Al interfaces strongly limits the performances of this fuel. Several in-pile tests have been performed to optimize the composition. In this paper, a breakthrough in simulating the U–8wt%Mo/Al behavior under out-of-pile irradiation is reported. It is shown that an amorphous U–8wt%Mo/Al interdiffusion layer (IDL) is obtained by heavy ion irradiation ( 127 I) in a U–Mo/Al diffusion couple under controlled temperature conditions. The properties of this IDL coincide with the results obtained from in-pile tests. This methodological work clearly indicates that heavy ion irradiations could be routinely applied for optimizing composition of U–Mo/Al nuclear fuels. In other words these out-of-pile tests using ion beams could become a representative, efficient and economic step before in-pile irradiation

  6. Partial absence of pleuropericardial membranes in Tbx18- and Wt1-deficient mice.

    Directory of Open Access Journals (Sweden)

    Julia Norden

    Full Text Available The pleuropericardial membranes are fibro-serous walls that separate the pericardial and pleural cavities and anchor the heart inside the mediastinum. Partial or complete absence of pleuropericardial membranes is a rare human disease, the etiology of which is poorly understood. As an attempt to better understand these defects, we wished to analyze the cellular and molecular mechanisms directing the separation of pericardial and pleural cavities by pleuropericardial membranes in the mouse. We found by histological analyses that both in Tbx18- and Wt1-deficient mice the pleural and pericardial cavities communicate due to a partial absence of the pleuropericardial membranes in the hilus region. We trace these defects to a persisting embryonic connection between these cavities, the pericardioperitoneal canals. Furthermore, we identify mesenchymal ridges in the sinus venosus region that tether the growing pleuropericardial membranes to the hilus of the lung, and thus, close the pericardioperitoneal canals. In Tbx18-deficient embryos these mesenchymal ridges are not established, whereas in Wt1-deficient embryos the final fusion process between these tissues and the body wall does not occur. We suggest that this fusion is an active rather than a passive process, and discuss the interrelation between closure of the pericardioperitoneal canals, lateral release of the pleuropericardial membranes from the lateral body wall, and sinus horn development.

  7. Effect of quench rate on the mechanical properties of U-6 wt % Nb

    International Nuclear Information System (INIS)

    Eckelmeyer, K.H.

    1980-03-01

    U-6 wt % Nb conventionally is water quenched from 800 0 C in order to obtain a niobium supersaturated α'' structure having good corrosion resistance and high ductility (125% tensile elongation). The high cooling rate associated with the water quench, however, produces undesirable distortion and residual stress. This study was conducted to determine the extent to which the quench rate could be reduced (in order to minimize the distortion and residual stress problems) without sacrificing properties. The results indicate that quench rate can be reduced by as much as a factor of 10 without any loss of ductility, and that a factor of 100 reduction in quench rate (as is produced by air cooling) still produces material with moderate ductility (> 12% tensile elongation). The results also indicate that supersaturated α'' structures are produced at all of these quench rates. This suggests that these reductions in quench rate should not have drastic adverse effects on corrosion resistance. Hence, it should not be possible to substantially reduce the magnitudes of the distortion and residual stress problems while retaining appreciable ductility and corrosion resistance in U-6 wt % Nb

  8. Evidence of amorphous interdiffusion layer in heavy ion irradiated U–8wt%Mo/Al interfaces

    Energy Technology Data Exchange (ETDEWEB)

    Chiang, H-Y. [Forschungsneutronenquelle Heinz Maier-Leibniz (FRM II), Technische Universität München Lichtenbergstr. 1, D-85747 Garching (Germany); Zweifel, T. [Forschungsneutronenquelle Heinz Maier-Leibniz (FRM II), Technische Universität München Lichtenbergstr. 1, D-85747 Garching (Germany); CEA, DEN, DEC, F-13108 St. Paul Lez Durance Cedex (France); Palancher, H., E-mail: herve.palancher@cea.fr [CEA, DEN, DEC, F-13108 St. Paul Lez Durance Cedex (France); Bonnin, A. [ESRF, 6 rue Jules Horowitz, 38042 Grenoble (France); Beck, L. [Tandembeschleuniger des Maier-Leibnitz-Labors (MLL), Am Coulombwall 6, D-85747 Garching (Germany); Weiser, P. [Walther Schottky Institut, Technische Universität München, Am Coulombwall 4, D-85747 Garching (Germany); Döblinger, M. [Department Chemie, Ludwig-Maximilians-Universität München (LMU), Butenandstr. 11, D-81377 München (Germany); Sabathier, C. [CEA, DEN, DEC, F-13108 St. Paul Lez Durance Cedex (France); Jungwirth, R.; Petry, W. [Forschungsneutronenquelle Heinz Maier-Leibniz (FRM II), Technische Universität München Lichtenbergstr. 1, D-85747 Garching (Germany)

    2013-09-15

    U–Mo/Al based nuclear fuels are worldwide considered as the most promising high density fuel for the conversion of high flux research and test reactors from highly enriched uranium to lower enrichment. However in-pile growth of an amorphous interdiffusion layer at the U–Mo/Al interfaces strongly limits the performances of this fuel. Several in-pile tests have been performed to optimize the composition. In this paper, a breakthrough in simulating the U–8wt%Mo/Al behavior under out-of-pile irradiation is reported. It is shown that an amorphous U–8wt%Mo/Al interdiffusion layer (IDL) is obtained by heavy ion irradiation ({sup 127}I) in a U–Mo/Al diffusion couple under controlled temperature conditions. The properties of this IDL coincide with the results obtained from in-pile tests. This methodological work clearly indicates that heavy ion irradiations could be routinely applied for optimizing composition of U–Mo/Al nuclear fuels. In other words these out-of-pile tests using ion beams could become a representative, efficient and economic step before in-pile irradiation.

  9. Analytical and experimental studies on the strain rate effects in penetration of 10wt % ballistic gelatin

    International Nuclear Information System (INIS)

    Liu, L; Jia, Z; Ma, X L; Fan, Y R

    2013-01-01

    This work concentrates on modeling the super-elastic behavior of 10wt% ballistic gelatin at 4°C and the mechanical responses at quasi-static and high-speed penetrations. Uniaxial compression and simple shearing experiments were carried out to determine the moduli in Mooney-Rivlin model describing the elastic behavior of gelatin at low strain rates. The failure mode is determined to be elastic fracture as the tensile stretch ratio exceeds a critical value. For high compression strain rates, the available results from the split Hopkinson pressure bar (SHPB) experiments for 10wt% gelatin were carefully examined and assessed. Linear relationship between the moduli and the strain rate is established. Based on these material parameters, an analytic solution of stress for the quasi-static and quasi-dynamic expansion of spherical cavity in gelatin is derived. As a consequence, the work needed to open unit volume of cavity, P s , which is the key parameter in studying penetration problems, is linearly increasing with the characteristic strain rate. The application of P s to our quasi-static and high-speed penetration experiments is discussed and assessed

  10. Outcome of patients with stage III or inoperable WT treated on the second United Kingdom WT protocol (UKWT2); a United Kingdom Children's Cancer Study Group (UKCCSG) study.

    Science.gov (United States)

    Grundy, R G; Hutton, C; Middleton, H; Imeson, J; Pritchard, J; Kelsey, A; Marsden, H B; Vujanic, G M; Taylor, R E

    2004-04-01

    The aims of UKWT2 included consolidating the results for stage III patients obtained in UKWT1 and improving the outcome for patients with inoperable tumours by giving vincristine, actinomycin-D and doxorubicin in an intensive schedule (Intensive AVA). The second UK WT trial (UKWT2) ran between July 1986 and September 1991 accruing 448 patients. One hundred and six patients were diagnosed and treated for stage III disease. Six had clear cell sarcoma of the kidney (CCSK) and seven had rhabdoid tumours of the kidney (RTK) and are analysed separately. One other patient was excluded from overall analysis. Ninety-two patients were followed for a median of 115 months. Seventy-five received standard chemotherapy and abdominal radiotherapy according to protocol. Seventeen had stage III disease at immediate nephrectomy, but radiotherapy was omitted by physician choice. Thirty-three patients had inoperable disease at diagnosis and received pre-nephrectomy chemotherapy. Overall survival (OS) at 4 years for stage III favourable histology (FH) patients receiving abdominal RT was 83% (CI: 73-89). For children with stage III disease in whom RT was omitted the OS was 82% (CI: 59-97) and for inoperable disease 94% (CI: 78-98). The overall and event-free survival (EFS) of children with stage III CCSK was 100% and was achieved with the majority of patients not receiving radiotherapy (CI: 48-100). Three of seven children with RTK are alive EFS and OS 43% (CI: 10-73). For patients treated by abdominal radiotherapy the overall local control rate was 94.4% (CI: 86.4-98.5*%), 96.7% (CI: 88.5-99.6%) for flank RT and 83.3% (51.6-98.0%) for whole abdominal radiotherapy (WRT). The outcome for stage III FH disease was similar to that reported for UKWT1 and NWTS-3. The combination of abdominal RT together with 3-drug chemotherapy achieves a high abdominal tumour control rate. Flank RT is probably sufficient for localised tumour rupture. The high cure rates for children in this trial with

  11. The influence of post-extrusion thermomechanical treatments on the tensile properties of Zr-2.5 wt% Nb alloy

    International Nuclear Information System (INIS)

    Fleck, R.G.; Shek, G.K.

    1983-01-01

    The production routes used for Zr-2.5 wt% Nb pressure tubes are described. Tensile results (UTS) from laboratory tests which simulated modified production routes are presented and compared to UTS values of actual pressure tubes. Strengthening of stress relieved Zr-2.5 wt% Nb is discussed in terms of: a) sub-grain formation; b) transformation of the second phase; and c) reorientation of the second phase relative to the matrix. The strength of cold worked Zr-2.5 wt% Nb is not influenced by the prior cold worked grain size. (author)

  12. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, W., E-mail: witorw@gmail.com [Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Bolfarini, C., E-mail: cbolfa@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Kiminami, C.S., E-mail: kiminami@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil); Botta, W.J., E-mail: wjbotta@ufscar.br [Departamento de Engenharia de Materiais, Universidade Federal de São Carlos, Rod. Washington Luiz, Km 235, 13565-905 São Carlos, SP (Brazil)

    2016-12-15

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}, Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8}. The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al{sub 5}Co{sub 2} and Al{sub 13}Co{sub 4} and are quasicrystalline approximants. Although the Al{sub 5}Co{sub 2} phase has already been reported in the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the presence of the monoclinic Al{sub 13}Co{sub 4} is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al{sub 13}Co{sub 4} phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al{sub 71}Co{sub 13}Fe{sub 8}Cr{sub 8} alloy, the compositions Al{sub 77}Co{sub 11}Fe{sub 6}Cr{sub 6} and Al{sub 76}Co{sub 19}Fe{sub 4}Cr{sub 1} were chosen to be within the region of formation of the quaternary extension of the Al{sub 13}Co{sub 4} phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system

  13. Assessment of phase constitution on the Al-rich region of rapidly solidified Al-Co-Fe-Cr alloys

    International Nuclear Information System (INIS)

    Wolf, W.; Bolfarini, C.; Kiminami, C.S.; Botta, W.J.

    2016-01-01

    The formation of quasicrystalline approximants in rapidly solidified Al-Co-Fe-Cr alloys was investigated. Alloys of atomic composition Al 71 Co 13 Fe 8 Cr 8 , Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were produced using melt spinning and arc melting methods and their microstructural characterization was carried out by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. Up to the present there is no consensus in the literature regarding the formation of quasicrystalline phase or quasicrystalline approximants in the Al 71 Co 13 Fe 8 Cr 8 alloy. This work presents, for the first time, a detailed structural characterization of selected alloys in the Al-Co-Fe-Cr system close to the atomic composition Al 71 Co 13 Fe 8 Cr 8 . The results indicated the samples to be composed, mostly, by two intermetallic phases, which are quaternary extensions of Al 5 Co 2 and Al 13 Co 4 and are quasicrystalline approximants. Although the Al 5 Co 2 phase has already been reported in the Al 71 Co 13 Fe 8 Cr 8 alloy, the presence of the monoclinic Al 13 Co 4 is now identified for the first time in the as cast state. In the binary Al-Co system a quasicrystalline phase is known to form in a rapidly solidified alloy with composition close to the monoclinic and orthorhombic Al 13 Co 4 phases. This binary quasicrystalline phase presents an average valence electron per atom (e/a) between 1.7 and 1.9; thus, in addition to the Al 71 Co 13 Fe 8 Cr 8 alloy, the compositions Al 77 Co 11 Fe 6 Cr 6 and Al 76 Co 19 Fe 4 Cr 1 were chosen to be within the region of formation of the quaternary extension of the Al 13 Co 4 phase and also within the (e/a) of 1.7 to 1.9. However, no quasicrystalline phase is present in any of the studied alloys. The Al-Co-Fe-Cr system, around the compositions studied, is composed of quaternary extensions of Al-Co intermetallic phases, which present solubility of Fe and Cr at Co atomic sites. - Highlights: •The Al rich region of the Al

  14. Self accommodation morphology of martensite variants in Zr-2.5wt%Nb alloy

    International Nuclear Information System (INIS)

    Srivastava, D.; Madangopal, K.; Banerjee, S.; Ranganathan, S.

    1993-01-01

    The role of self accommodation of the different martensite variants in controlling the morphologies of the Zr-2.5wt%Nb alloy martensite has been examined. Three distinct types of grouping of martensite variants have been found to be predominantly present. Crystallographic descriptions of these groups have been provided and the degrees of self accommodation for these have been estimated and compared with those corresponding to other possible variant groupings around the symmetry axes of the parent phase. The frequently observed 3-variant group, which shows an indentation mark morphology when viewed along β directions in the transmission electron microscope, has been seen to have the highest degree of self accommodation amongst the cases considered. Based on the observations made, a growth sequence leading to the formation of the final martensitic structure has been proposed

  15. Deformation effect on recrystallization of Al-3.94 wt%Cu alloy

    International Nuclear Information System (INIS)

    Higgy, H.R.; Abou-El Nasr, T.Z.A.; Higgy, E.S.M.; Taha, A.M.S.

    1981-01-01

    The effect of cold-work and annealing temperature on the recrystallization of Al-3.94 wt%Cu was studied. As-received materials were annealed at both 400 0 C and 500 0 C before cold rolling. Cold-rolled specimens having 13%, 30%, 51% and 67% coldwork were isothermally annealed till 500 0 C, and then microscopically studied and hardness tested. Recrystallization process was found to be influenced by both deformation and annealing temperature. Grain-size increased with annealing temperature until 400 0 C, after which grain-size decreased. Cold-work decreased grain-size at all annealing temperatures. Hardness decreased with annealing temperature until 400 0 C, after which it increased sharply. Cold-work increased hardness, the increase was more pronounced at annealing temperatures below 400 0 C. (author)

  16. Mechanical properties of Al2O3-doped (2 wt.%) ZnO films

    International Nuclear Information System (INIS)

    Kuriki, Shina; Kawashima, Toshitaka

    2007-01-01

    We report a new method of evaluating the adhesion of Al 2 O 3 -doped (2 wt.%) ZnO (AZO) thin films. The AZO films were deposited by DC reactive magnetron sputtering on plastic film (PET: polyethyleneterephthalate) at various sputtering pressures, power, and reactive gas-flow ratios. The adhesion test of the films was carried out using the nanoindentation system. The fracture point as determined by the load-displacement curve occurred at the time of separation between the thin film and the substrate. The integration value of load and displacement to the fracture point is defined as the degree of adhesion (S W ). The AZO films showed that adhesion increase as sputtering power increases and sputtering pressure decreases

  17. Measurement of effective solvus temperature of hydrogen in Zr - 2. 5 wt % Nb using acoustic emission

    Energy Technology Data Exchange (ETDEWEB)

    Coleman, C.E.; Ambler, J.F.R.

    1978-01-01

    The effect of applied tensile stress on the solvus temperature of hydrogen in cold-worked Zr - 2.5 wt % Nb has been measured using acoustic emission. Hydrides are necessary for delayed hydrogen cracking and the lowest temperature at which hydride cracking cannot be detected by acoustic emission was taken as the solvus temperature. The results show that any effect of tensile stress on terminal solubility, Cs, is undetectable. Between about 2 and 100 ppM hydrogen, the results can be described by: C/sub s/ = 1.40 x 10/sup 5/ exp - (36100/RT) ppM. They also suggest that the equilibrium phase, delta-hydride, is responsible for delayed hydrogen cracking.

  18. Porosity Effect on Thermal Properties of Al-12 wt % Si/Graphite Composites

    Directory of Open Access Journals (Sweden)

    José-Miguel Molina

    2017-02-01

    Full Text Available The effect of porosity on the thermal conductivity and the coefficient of thermal expansion of composites obtained by infiltration of Al-12 wt % Si alloy into graphite particulate preforms has been determined. Highly irregular graphite particles were used to fabricate the preforms. The thermal conductivity of these composites gradually increases with the applied infiltration pressure given the inherent reduction in porosity. A simple application of the Hasselman-Johnson model in a two-step procedure (that accounts for the presence of both graphite particles and voids randomly dispersed in a metallic matrix offers a good estimation of the experimental results. As concerns the coefficient of thermal expansion, the results show a slight increase with saturation being approximately in the range 14.6–15.2 × 10−6 K−1 for a saturation varying from 86% up to 100%. Results lie within the standard Hashin-Strikman bounds.

  19. Porosity Effect on Thermal Properties of Al-12 wt % Si/Graphite Composites.

    Science.gov (United States)

    Molina, José-Miguel; Rodríguez-Guerrero, Alejandro; Louis, Enrique; Rodríguez-Reinoso, Francisco; Narciso, Javier

    2017-02-14

    The effect of porosity on the thermal conductivity and the coefficient of thermal expansion of composites obtained by infiltration of Al-12 wt % Si alloy into graphite particulate preforms has been determined. Highly irregular graphite particles were used to fabricate the preforms. The thermal conductivity of these composites gradually increases with the applied infiltration pressure given the inherent reduction in porosity. A simple application of the Hasselman-Johnson model in a two-step procedure (that accounts for the presence of both graphite particles and voids randomly dispersed in a metallic matrix) offers a good estimation of the experimental results. As concerns the coefficient of thermal expansion, the results show a slight increase with saturation being approximately in the range 14.6-15.2 × 10 -6 K -1 for a saturation varying from 86% up to 100%. Results lie within the standard Hashin-Strikman bounds.

  20. Recovery of the mechanical properties on the Al-4wt%Cu alloy

    International Nuclear Information System (INIS)

    Chemingui, M; Kassis, K; Khitouni, M; Masmoudi, J; Kolsi, A W

    2010-01-01

    The recovery of the mechanical properties on the Al-4%wtCu alloy was investigated by indentation after cold rolling. The microstructural evolution was performed using optical and scanning electron microscopies. The annealing at 200 deg. C of the quenched and rolled alloy gives higher mechanical qualities. At temperatures up to 200 deg. C, the alloy has no softening by recovery, but on the contrary a hardening behaviour was observed. This later is attributed to the presence of the intermediate θ'' and θ' phases. Nevertheless, the ageing in high temperature product the coalescence of iron particles and of Al 2 Cu precipitates. These phases are essentially localized in the grain boundaries, which caused the damage of the alloy.

  1. δ' precipitation in a binary Al-3.2 Wt % Li alloy

    International Nuclear Information System (INIS)

    Mahadev, V.; Mahalingam, K.; Liedl, G.L.; Sanders, T.H. Jr.

    1992-01-01

    This paper reports on a study of the early stages of Al 3 Li(δ') precipitation in a binary Al-3.2wt% Li alloy that was performed by X-ray scattering experiments. Efforts were made to understand the very early stages of precipitation. Particle size measurements were made on samples in the as quenched state and after isothermally aging for various times ranging from 5 minutes to 10 days at 433K, 453K and 473K. Short range order parameters and average atomic displacements were determined for early aging times. A simple simulation model based upon the particle size distribution is proposed to examine the implications of the experimental observations. This simulation fits the assumption that the particles are fully ordered and coherent with the matrix even in the very early stages of aging. Kinetics of the early stages were found to be consistent with data obtained for longer aging times and supports an early growth stage

  2. Microstructural and mechanical characterization of Cu-0.8 wt.%Y

    International Nuclear Information System (INIS)

    Carro, G.; Muñoz, A.; Monge, M.A.; Savoini, B.; Pareja, R.

    2015-01-01

    Dispersion strengthened Cu-0.8 wt.%Y has been produced by a powder metallurgy route and subsequent consolidation by hot isostatic pressing at 1123 K and 172 MPa. A fully dense alloy has been obtained that exhibits a microstructure characterized by equiaxed grains with sizes ranging from 0.5 to 50 μm. Yttrium-rich particles with an average size of 0.92 μm have been observed inside the grains and decorating the grain boundaries. As expected, the tensile tests carried out from room temperature to 773 K have revealed that both the YS and the UTS decrease with increasing temperature. This alloy exhibits better tensile properties and microhardness than OFHC Cu. This improvement is attributed to the presence of the Y-rich particles.

  3. Microstructural and mechanical characterization of Cu-0.8 wt.%Y

    Energy Technology Data Exchange (ETDEWEB)

    Carro, G., E-mail: gcarro@fis.uc3m.es; Muñoz, A.; Monge, M.A.; Savoini, B.; Pareja, R.

    2015-10-15

    Dispersion strengthened Cu-0.8 wt.%Y has been produced by a powder metallurgy route and subsequent consolidation by hot isostatic pressing at 1123 K and 172 MPa. A fully dense alloy has been obtained that exhibits a microstructure characterized by equiaxed grains with sizes ranging from 0.5 to 50 μm. Yttrium-rich particles with an average size of 0.92 μm have been observed inside the grains and decorating the grain boundaries. As expected, the tensile tests carried out from room temperature to 773 K have revealed that both the YS and the UTS decrease with increasing temperature. This alloy exhibits better tensile properties and microhardness than OFHC Cu. This improvement is attributed to the presence of the Y-rich particles.

  4. Delayed hydride cracking in Zr-2.5% wt Nb pressure tubes

    International Nuclear Information System (INIS)

    Cirimello, Pablo; Haddad, Roberto; Domizzi, Gladys

    2003-01-01

    During service, pressure tubes of CANDU nuclear power reactor are prone to suffer crack growth by delayed hydride cracking (DHC). For a given H 2 plus D 2 concentration there is a critical temperature (T c ) below which DHC may occur. In this work, T c was measured for CCT specimens cut from Zr-2.5 Wt % Nb pressure tubes. Hydrogen was added to the specimens to get concentrations of 40, 59 and 72 ppm. It was found that T c is higher than the corresponding precipitation temperature. The axial crack velocity (V p ) was also measured. Decreasing temperature from T c makes V p increase until a maximum is attained at a temperature close to precipitation temperature. At lower temperatures, in the presence of precipitated hydrides, decreasing temperature implies lower velocities, following an Arrhenius law: Vp=Aexp(-Q/RT), with an activation energy Q= 66 KJ/mol K. (author)

  5. Stress corrosion cracking of 350 maraging steel in 3.5 Wt. % NaCl solution

    International Nuclear Information System (INIS)

    Hussain, I.; Hussain, T.; Tauqir, A.; Hashmi, F.H.; Khan, A.Q.

    1993-01-01

    Stress corrosion behavior of 350 maraging steel in 3.5 wt.% NaCl solution was investigated. The results suggest that the steel is susceptible to stress corrosion cracking as the time to failure was always considerably shorter, as compared to those in air at the same stress level. The fracture mode was nearly intergranular and occasionally transgranular. There was no definite trend for the different modes of failure. The strain rate effect was also considered and the results show that the stress corrosion cracks were absent at strain rate high than 1.97 x 10/sup -4/S/sup -1/ and lower than 1.29 x 10/sup -7/S/sup -1/. The critical strain rate range was found to be between 6.4 x 10/sup -7/ to 3.24 x10/sup -5/S /sup -1/. (author)

  6. The effect of thermomechanical processing on second phase particle redistribution in U-10 wt%Mo

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Xiaohua; Wang, Xiaowo; Joshi, Vineet V.; Lavender, Curt A.

    2018-03-01

    The multi-pass hot-rolling process of an annealed uranium-10 wt% molybdenum coupon was studied by plane-strain compression finite element modeling. Two point correlation function (2PCF) was used to analyze the carbide particle distribution after each rolling reduction. The hot rolling simulation results show that the alignment of UC particles along grain boundaries will rotate during rolling until it is parallel to the rolling direction, to form stringer-like distributions which are typically observed in rolled products that contain inclusions. 2PCF analysis of simulation shows that the interparticle spacing shrinks along the normal direction. The number of major peaks of 2PCF along ND decreases after large reduction. The locations of major peaks indicate the inter-stringer distances.

  7. The Synthesis and Characterization of W- 1wt.% TiC Alloy Using a Chemical Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Taehee; Ryu, Ho Jin [KAIST, Daejeon (Korea, Republic of)

    2016-10-15

    The tungsten and its alloys have been used in many applications due to their excellent mechanical and thermal properties such as high melting point, high thermal conductivity, high strength at elevated temperatures, low sputtering yield in radiation environment and low tritium inventory. Moreover, many researchers consider tungsten alloys as the most promising candidate for plasma facing components for future nuclear fusion reactors. Three samples of W – 1.0 wt.% TiC composites with the different fabrication methods were successfully developed. The combined method of the wet chemical method and 3D mixing showed small amount of agglomeration of TiC particles, however, the TiC particle sizes were smaller than 3DM1 sample. Since the WCM1 showed the better mechanical property, microhardness, the main future plan is to achieve the same or improved mechanical property of W3D1.

  8. β-85 wt % Nb precipitates: the effect on in-reactor diametric creep of pressure tubes

    International Nuclear Information System (INIS)

    Sarce, Alicia

    2006-01-01

    By linking the microstructure evolution of an α-Zr crystal with the macroscopic behaviour, the deformation of an in-service reactor pressure tube is calculated. Microstructure evolution is considered through rate theory modelling of the interaction between point defects and sinks. Different densities of β-85 wt % Nb precipitates are proposed to be distributed inside the α grains and act as point defect sinks, doing a screening effect on the grain boundaries. From the interatomic pair potential which is used to describe the material, positive tangential deformation rates (on the other hand negatives) are obtained when these densities in the c-crystal direction are bigger than a minimum value. (author) [es

  9. The variation of work hardening characteristics of Al-5 wt% Mg alloy during phase transition

    International Nuclear Information System (INIS)

    Mahmoud, M.A.; Sobhy, M.; Abd El-Rehim, A.F.; Abdel Rahman, R.M.

    2010-01-01

    The aim of this study is to investigate the effect of aging conditions on the stress-strain behavior along with microstructure changes of the Al-5 wt% Mg alloy. Following solid solution treatment and aging of specimens at temperatures ranging from 373 to 573 K for various aging times (1/4 to 4 h), stress-strain tests were performed at different testing temperatures (313-343 K). The work hardening parameters (σ y , σ f , χ p and Y) were found to decrease continuously with pre-aging times at all aging and testing temperatures, where the softening parameters (ε f and L) oppose this behavior. The variation in stress-strain parameters with increasing aging temperatures and aging times was explained on the basis of structural transformations taking place in the Al-Mg alloy. A precipitate-dislocation intersections mechanism was assumed as the rate-controlling mechanism for alloy.

  10. Mechanical characterization of cemented carbide WC-6Co (%wt) manufactured by SPS (Spark Plasma Sintering

    International Nuclear Information System (INIS)

    Boidi, G.; Tertuliano, A.J.; Machado, I.F.

    2016-01-01

    This work aimed to manufacture cemented carbide (WC-6%wtCo) obtained by SPS (Spark Plasma Sintering) process and to carry out the mechanical characterization by hardness and fracture toughness. The material was consolidated at 1100 deg C for different holding times (1 min, 5 min, 10 min), in order to evaluate the densification. A reference sample was also used to be compared to SPS. Optical and scanning electron microscopy were carried out to characterize the microstructural features of the samples and mechanical properties were obtained by hardness measurements (micro and macro) and instrumented indentation. The fracture toughness was calculated with the method of Palmqvist. Best results were found in the material sintered by SPS for 10 minutes of holding time, in which 97% of relative density and about 1600 HV_1_0 was reached. (author)

  11. Measurement and modeling of room temperature co-deformation in WC-10 wt.%

    Energy Technology Data Exchange (ETDEWEB)

    Livescu, V. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)]. E-mail: vlivescu@lanl.gov; Clausen, B. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Paggett, J.W. [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211 (United States); Krawitz, A.D. [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, MO 65211 (United States); Drake, E.F. [REEDHycalogTM/Grant Prideco, Houston, TX 77252 (United States); Bourke, M.A.M. [MST-8/LANSCE, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2005-06-15

    In situ neutron diffraction measurements were performed on a tungsten carbide (WC)-10 wt.% cobalt (Co) cemented carbide composite subjected to compressive loading. The sample was subjected to consecutive load/unload cycles to -500, -1000, -2000 and -2100 MPa. Thermal residual stresses measured before loading reflected large hydrostatic tensile stresses in the binder phase and compressive stresses in the carbide phase. The carbide phase behaved elastically at all but the highest load levels, whereas plasticity was present in the binder phase from values of applied stress as low as -500 MPa. A finite element simulation utilizing an interpenetrating microstructure model showed remarkable agreement with the complex mean phase strain response during the loading cycles despite its under-prediction of thermal residual strains.

  12. Investigation of powdering ductile gamma U-10 wt%Mo alloy for dispersion fuels

    Energy Technology Data Exchange (ETDEWEB)

    Leal Neto, R.M., E-mail: lealneto@ipen.br [Nuclear and Energy Research Institute, IPEN/CNEN-SP, São Paulo (Brazil); Rocha, C.J. [Nuclear and Energy Research Institute, IPEN/CNEN-SP, São Paulo (Brazil); Urano de Carvalho, E. [Nuclear and Energy Research Institute, IPEN/CNEN-SP, São Paulo (Brazil); Science and Technology Brazilian Institute, Innovating Nuclear Reactors (Brazil); Riella, H.G. [Science and Technology Brazilian Institute, Innovating Nuclear Reactors (Brazil); Chemical Engineering Department, Santa Catarina Federal University, Florianópolis (Brazil); Durazzo, M. [Nuclear and Energy Research Institute, IPEN/CNEN-SP, São Paulo (Brazil); Science and Technology Brazilian Institute, Innovating Nuclear Reactors (Brazil)

    2014-02-01

    This work forms part of the studies presently ongoing at Nuclear and Energy Research Institute – IPEN/CNEN-SP investigating the feasibility of powdering ductile U-10 wt%Mo alloy by hydriding–milling–dehydriding of the gamma phase (HMD). Hydriding was conducted at room temperature in a Sievert apparatus following heat treatment activation. Hydrided pieces were fragile enough to be hand milled to the desired particle size range. Hydrogen was removed by heating the samples under high vacuum. X-ray diffraction analysis of the hydrided material showed an amorphous-like pattern that is completely reversed following dehydriding. The hydrogen content of the hydrided samples corresponds to a trihydride, i.e. (U,Mo)H{sub 3}. SEM analysis of HMD powder particles revealed equiaxial powder particles together with some plate-like particles. A hypothesis for the amorphous hydride phase formation is suggested.

  13. Effect of silver and indium addition on mechanical properties and indentation creep behavior of rapidly solidified Bi–Sn based lead-free solder alloys

    International Nuclear Information System (INIS)

    Shalaby, Rizk Mostafa

    2013-01-01

    Mechanical properties and indentation creep of the melt-spun process Bi–42 wt%Sn, Bi–40 wt%Sn–2 wt%In, Bi–40 wt%Sn–2 wt%Ag and Bi–38 wt%Sn–2 wt%In–2 wt%Ag were studied by dynamic resonance technique and Vickers indentation testing at room temperature and compared to that of the traditional Sn–37 wt%Pb eutectic alloy. The results show that the structure of Bi–42 wt%Sn alloy is characterized by the presence of rhombohedral Bi and body centered tetragonal β-Sn. The two ternary alloys exhibit additional constituent phases of intermetallic compounds SnIn 19 for Bi–40 wt%Sn–2 wt%In and ε-Ag 3 Sn for Bi–40 wt%Sn–2 wt%Ag alloys. Attention has been paid to the role of intermetallic compounds on mechanical and creep behavior. The In and Ag containing solder alloy exhibited a good combination of higher creep resistance, good mechanical properties and lower melting temperature as compared with Pb–Sn eutectic solder alloy. This was attributed to the strengthening effect of Bi as a strong solid solution element in the Sn matrix and formation of intermetallic compounds β-SnBi, ε-Ag 3 Sn and InSn 19 which act as both strengthening agent and grain refiner in the matrix of the material. Addition of In and Ag decreased the melting temperature of Bi–Sn lead-free solder from 143 °C to 133 °C which was possible mainly due to the existence of InSn 19 and Ag 3 Sn intermetallic compounds. Elastic constants, internal friction and thermal properties of Bi–Sn based alloys have been studied and analyzed.

  14. Fabrication of U-10wt.%Zr Fuel slug for SFR by Injection Casting

    International Nuclear Information System (INIS)

    Kim, Jong Hwan; Song, Hoon; Kim, Hyung Tae; Ko, Young Mo; Kim, Ki Hwan; Lee, Chan B.

    2013-01-01

    The fabrication technology of metal fuel has been developed by various methods such as rolling, swaging, wire drawing, and co-extrusion, but each of these methods had process limitations requiring an additional subsequent process, and needing the fabrication equipment is complex, which is not favorable for remote use. A practical process of metallic fuel fabrication for an SFR needs to be cost efficient, suitable for remote operation, and capable of mass production while reducing the amount of radioactive waste. Injection casting was chosen as the most promising technique, in the early 1950s, and this technique has been applied to fuel slug fabrication for the Experimental Breeder Reactor-II (EBR-II) driver and the Fast Flux Test Facility (FFTF) fuel pins. Because of the simplistic nature of the process and equipment, compared to other processes examined, this process has been successfully used in a remote operation environment for fueling of the EBR-II reactor. In this study, vacuum injection casting suitable for remote operation has been developed to fabricate metallic fuel for an SFR. Vacuum injection casting technique was developed to fabricate metallic fuel for an SFR. The appearance of the fabricated U-10wt.%Zr fuel was generally sound and the internal integrity was found to be satisfactory through gamma-ray radiography. Minimum fuel losses after casting relative to the initial charge amount of U-10wt.%Zr fuel slugs met the proposed goal of less than 0.1% fuel losses during fabrication. Modifications of the current facility system and advanced casting techniques are underway to produce higher quality fuel slugs

  15. Fabrication of U-10wt.%Zr Fuel slug for SFR by Injection Casting

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Hwan; Song, Hoon; Kim, Hyung Tae; Ko, Young Mo; Kim, Ki Hwan; Lee, Chan B. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    The fabrication technology of metal fuel has been developed by various methods such as rolling, swaging, wire drawing, and co-extrusion, but each of these methods had process limitations requiring an additional subsequent process, and needing the fabrication equipment is complex, which is not favorable for remote use. A practical process of metallic fuel fabrication for an SFR needs to be cost efficient, suitable for remote operation, and capable of mass production while reducing the amount of radioactive waste. Injection casting was chosen as the most promising technique, in the early 1950s, and this technique has been applied to fuel slug fabrication for the Experimental Breeder Reactor-II (EBR-II) driver and the Fast Flux Test Facility (FFTF) fuel pins. Because of the simplistic nature of the process and equipment, compared to other processes examined, this process has been successfully used in a remote operation environment for fueling of the EBR-II reactor. In this study, vacuum injection casting suitable for remote operation has been developed to fabricate metallic fuel for an SFR. Vacuum injection casting technique was developed to fabricate metallic fuel for an SFR. The appearance of the fabricated U-10wt.%Zr fuel was generally sound and the internal integrity was found to be satisfactory through gamma-ray radiography. Minimum fuel losses after casting relative to the initial charge amount of U-10wt.%Zr fuel slugs met the proposed goal of less than 0.1% fuel losses during fabrication. Modifications of the current facility system and advanced casting techniques are underway to produce higher quality fuel slugs.

  16. Active Tension Control for WT Wheelchair Robot by Using a Novel Control Law for Holonomic or Nonholonomic Systems

    Directory of Open Access Journals (Sweden)

    Jian Wang

    2013-01-01

    Full Text Available Interactional characteristics between WT wheelchair robot and stair environment are analyzed, and possible patterns of WT wheelchair robot during the stair-climbing process are summarized, with the criteria of the wheelchair robot for determining the pattern proposed. Aiming at WT wheelchair robot's complicated mechanism with holonomic constraints and combined with the computed torque method, a novel control law that is called active tension control is presented for holonomic or nonholonomic robotic systems, by which the wheelchair robot with a holonomic or nonholonomic mechanism can track the reference input of the constraint forces of holonomic or nonholonomic constraints as well as tracking the reference input of the generalized coordinate of each joint. A stateflow module of Matlab is used to simulate the entire stair-climbing process for WT wheelchair robot. A comparison of output curve with the reference input curve of each joint is made, with the effectiveness of the presented control law verified.

  17. TTP SR1-6-WT-31, Milestone C.3-2 Annual Report on Clemson/INEEL Melter Work

    Energy Technology Data Exchange (ETDEWEB)

    Bickford, D.F.

    1999-10-20

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements.

  18. TTP SR1-6-WT-31, Milestone C.3-2 Annual Report on Clemson/INEEL Melter Work

    International Nuclear Information System (INIS)

    Bickford, D.F.

    1999-01-01

    This work is performed in collaboration with RL37WT31-C and ID77WT31-B. During the first two years of radioactive operation of the DWPF process, several areas for improvement in melter design have been identified. The continuing scope of this task is to address performance limitations and deficiencies identified by the user. SRS will design and test several configurations of the melter pour spout and associated equipment to improve consistency of performance and recommend design improvements

  19. A Novel WT1 Gene Mutation in a Three-Generation Family with Progressive Isolated Focal Segmental Glomerulosclerosis

    Science.gov (United States)

    Caridi, Gianluca; Malaventura, Cristina; Dagnino, Monica; Leonardi, Emanuela; Artifoni, Lina; Ghiggeri, Gian Marco; Tosatto, Silvio C.E.; Murer, Luisa

    2010-01-01

    Background and objectives: Wilms tumor-suppressor gene-1 (WT1) plays a key role in kidney development and function. WT1 mutations usually occur in exons 8 and 9 and are associated with Denys-Drash, or in intron 9 and are associated with Frasier syndrome. However, overlapping clinical and molecular features have been reported. Few familial cases have been described, with intrafamilial variability. Sporadic cases of WT1 mutations in isolated diffuse mesangial sclerosis or focal segmental glomerulosclerosis have also been reported. Design, setting, participants, & measurements: Molecular analysis of WT1 exons 8 and 9 was carried out in five members on three generations of a family with late-onset isolated proteinuria. The effect of the detected amino acid substitution on WT1 protein's structure was studied by bioinformatics tools. Results: Three family members reached end-stage renal disease in full adulthood. None had genital abnormalities or Wilms tumor. Histologic analysis in two subjects revealed focal segmental glomerulosclerosis. The novel sequence variant c.1208G>A in WT1 exon 9 was identified in all of the affected members of the family. Conclusions: The lack of Wilms tumor or other related phenotypes suggests the expansion of WT1 gene analysis in patients with focal segmental glomerulosclerosis, regardless of age or presence of typical Denys-Drash or Frasier syndrome clinical features. Structural analysis of the mutated protein revealed that the mutation hampers zinc finger-DNA interactions, impairing target gene transcription. This finding opens up new issues about WT1 function in the maintenance of the complex gene network that regulates normal podocyte function. PMID:20150449

  20. Ordering and reaccomodation processes for defects in Fe-6.5wt.% Si and its influence on magnetic properties

    International Nuclear Information System (INIS)

    Cano, J.A; Lambri, O.A; Perez-Landazabal, J.I; Recarte, V

    2004-01-01

    Mechanical spectroscopy (MS) and magnetic hysteresis measurements were carried out in order to thoroughly study the effects of the order and reactions of the super dislocations in commercial alloys of Fe-6.5wt.% Si and Fe-3wt% Si with GOSS [110] texture during 1 hour, in a high vacuum, followed by tempering in water. The test pieces that were measured came from cut sheets provided by NKK Corp. The deadening and elastic module measurements were done with an inverted torsion pendulum, inside of which a 10 -5 Pa vacuum was made, expressed as a function of the temperature, and reaching three different final values: 973K, 1050K and 1273K. The magnetic measurements were carried out with an electromagnetic system that traced the hysteresis cycles. The behavior of deadening and the elastic module spectrum in Fe-6.5wt% Si is controlled by the relationship between the maximum temperature reached in the pendulum and the order-disorder transformation temperature. This dependence does not appear in the Fe-3wt% Si with GOSS [110] texture. The quenching defects recovery effects in Fe-3wt% Si are less than for the Fe-6.5wt% Si because of the absence of super dislocations and anti phase borders (APB) (CW)

  1. Reduction in WT1 gene expression during early treatment predicts the outcome in patients with acute myeloid leukemia.

    Science.gov (United States)

    Andersson, Charlotta; Li, Xingru; Lorenz, Fryderyk; Golovleva, Irina; Wahlin, Anders; Li, Aihong

    2012-12-01

    Wilms tumor gene 1 (WT1) expression has been suggested as an applicable minimal residual disease marker in acute myeloid leukemia (AML). We evaluated the use of this marker in 43 adult AML patients. Quantitative assessment of WT1 gene transcripts was performed using real-time quantitative-polymerase chain reaction assay. Samples from both the peripheral blood and the bone marrow were analyzed at diagnosis and during follow-up. A strong correlation was observed between WT1 normalized with 2 different control genes (β-actin and ABL1, P0.05). A≥1-log reduction in WT1 expression in bone marrow samples taken freedom from relapse (P=0.010) when β-actin was used as control gene. Furthermore, a reduction in WT1 expression by ≥2 logs in peripheral blood samples taken at a later time point significantly correlated with a better outcome for overall survival (P=0.004) and freedom from relapse (P=0.012). This result was achieved when normalizing against both β-actin and ABL1. These results therefore suggest that WT1 gene expression can provide useful information for minimal residual disease detection in adult AML patients and that combined use of control genes can give more informative results.

  2. Strain-softening behavior of an Fe-6.5 wt%Si alloy during warm deformation and its applications

    International Nuclear Information System (INIS)

    Fu Huadong; Zhang Zhihao; Yang Qiang; Xie Jianxin

    2011-01-01

    Research highlights: → An Fe-6.5 wt%Si alloy exhibits strain-softening behavior after large deformation. → The decrease of the order degree is responsible for the strain-softening behavior. → The strain-softening behavior of Fe-6.5 wt%Si alloy can be applied in cold rolling. → An Fe-6.5 wt%Si thin strip with thickness of 0.20 mm is fabricated by cold rolling. - Abstract: An Fe-6.5 wt%Si alloy with columnar grains was compressed at a temperature below its recrystallization temperature. The Vickers hardness and structure of the alloy before and after deformation were investigated. The results showed that with an increase in the degree of deformation, Vickers hardness of the alloy initially increased rapidly and then decreased slowly, indicating that the alloy had a strain-softening behavior after a large deformation. Meanwhile, the work-hardening exponent of the alloy decreased significantly. Transmission electron microscopy confirmed that the decrease of the order degree was responsible for the strain-softening behavior of the deformed alloy. Applying its softening behavior, the Fe-6.5 wt%Si alloy with columnar grains was rolled at 400 deg. C and then at room temperature. An Fe-6.5 wt%Si thin strip with thickness of 0.20 mm was fabricated. The surface of the strip was bright and had no obvious edge cracks.

  3. WT1 Is Necessary for the Proliferation and Migration of Cells of Renin Lineage Following Kidney Podocyte Depletion

    Directory of Open Access Journals (Sweden)

    Natalya V. Kaverina

    2017-10-01

    Full Text Available Wilms' tumor suppressor 1 (WT1 plays an important role in cell proliferation and mesenchymal-epithelial balance in normal development and disease. Here, we show that following podocyte depletion in three experimental models, and in patients with focal segmental glomerulosclerosis (FSGS and membranous nephropathy, WT1 increased significantly in cells of renin lineage (CoRL. In an animal model of FSGS in RenWt1fl/fl reporter mice with inducible deletion of WT1 in CoRL, CoRL proliferation and migration to the glomerulus was reduced, and glomerular disease was worse compared with wild-type mice. To become podocytes, CoRL undergo mesenchymal-to-epithelial transformation (MET, typified by reduced staining for mesenchymal markers (MYH11, SM22, αSMA and de novo expression of epithelial markers (E-cadherin and cytokeratin18. Evidence for changes in MET markers was barely detected in RenWt1fl/fl mice. Our results show that following podocyte depletion, WT1 plays essential roles in CoRL proliferation and migration toward an adult podocyte fate.

  4. Electrodeposition, characterization and corrosion behaviour of tin-20 wt.% zinc coatings electroplated from a non-cyanide alkaline bath

    International Nuclear Information System (INIS)

    Dubent, S.; Mertens, M.L.A.D.; Saurat, M.

    2010-01-01

    Tin-zinc alloy electroplated coatings are recognized as a potential alternative to toxic cadmium as corrosion resistant deposits because they combine the barrier protection of tin with the cathodic protection afforded by zinc. The coatings containing 20 wt.% zinc, balance tin, offer excellent corrosion protection for steel and do not form gross voluminous white corrosion products like pure zinc or high zinc alloy deposits. In this study, the effects of variables of the process (i.e. cathodic current density, pH and temperature) on deposit composition have been evaluated using a Hull cell to obtain 20 wt.% zinc alloy coatings. The tin-20 wt.% zinc deposits, produced with electroplating optimized conditions, were characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDS), X-ray fluorescence spectrometry (XRF) and glow discharge optical emission spectrometry (GDOES). On the other hand, the corrosion behaviour of tin-zinc alloy electroplated coatings on steel has been investigated using electrochemical methods in a 3 wt.% NaCl solution and the salt spray test. The performance of the deposits was compared with cadmium and zinc-nickel electrodeposited coatings. The results show that the corrosion resistance of tin-20 wt.% zinc alloy coating is superior to that of cadmium and zinc-12 wt.% nickel coatings. Finally, sliding friction tests were conducted.

  5. Influence of micro-additions of bismuth on structures, mechanical and electrical transport properties of rapidly solidified Sn-3.5% Ag Alloy from melt

    International Nuclear Information System (INIS)

    El Bahay, M.M.; Mady, H.A.

    2005-01-01

    The present study was undertaken to investigate the influence of the Bi addition in the Sn-3.5 Ag rapidly solidified binary system for use as a Pb-free solder. The resulting properties of the binary system were extended to the Sn based ternary systems Sn 9 6.5-X Ag 3 .5 Bi x (0≤ X ≤ 2.5) solder. The structure and electrical resistivity of rapidly solidified (melt spun) alloys have been investigated. With the addition of up to 2.5 mass % Bi, the melting temperature decreases from 221.1 to 214.8 degree C. Wetting contact angle of the six alloys on Cu Zn 3 0 substrate are carried out at 573 K. Microhardness evaluations were also performed on the Sn-Ag-Bi alloys. The measured values and other researcher's results were compared with the calculated data

  6. Variation of long-period stacking order structures in rapidly solidified Mg97Zn1Y2 alloy

    International Nuclear Information System (INIS)

    Matsuda, M.; Ii, S.; Kawamura, Y.; Ikuhara, Y.; Nishida, M.

    2005-01-01

    The long-period stacking order (LPSO) structures in rapidly solidified Mg 97 Zn 1 Y 2 alloy have been studied by conventional and high-resolution transmission electron microscopes (HRTEMs). There are four kinds of stacking sequences in the LPSO structures, i.e., 18R of ABABABCACACABCBCBC, 14H of ACBCBABABABCBC, 10H of ABACBCBCAB and 24R of ABABABABCACACACABCBCBCBC. The 18R structure is dominantly observed in the present study. The rest three are occasionally observed in places. The 10H and 24R structures are recently discovered. The lattice constants of 18R(1-bar 1-bar -bar 1-bar 1-bar -bar 2) 3 , 14H(2-bar -bar 1-bar 2-bar -bar 1-bar 1-bar -bar 1-bar 1-bar -bar 2-bar 1-bar -bar 2), 10H(1-bar 3-bar -bar 1-bar 1-bar -bar 3-bar 1-bar ) and 24R(1-bar 1-bar -bar 1-bar 1-bar -bar 1-bar 1-bar -bar 2) 3 structures are estimated to be a=0.320nm and c=4.678nm, a=0.325nm and c=3.694nm, a=0.325nm and c=2.603nm, a=0.322nm and c=6.181nm for the hexagonal structure, respectively

  7. Formation of equiaxed crystal structures in directionally solidified Al-Si alloys using Nb-based heterogeneous nuclei

    Science.gov (United States)

    Bolzoni, Leandro; Xia, Mingxu; Babu, Nadendla Hari

    2016-01-01

    The design of chemical compositions containing potent nuclei for the enhancement of heterogeneous nucleation in aluminium, especially cast alloys such as Al-Si alloys, is a matter of importance in order to achieve homogeneous properties in castings with complex geometries. We identified that Al3Nb/NbB2 compounds are effective heterogeneous nuclei and are successfully produced in the form of Al-2Nb-xB (x = 0.5, 1 and 2) master alloys. Our study shows that the inoculation of Al-10Si braze alloy with these compounds effectively promotes the heterogeneous nucleation of primary α-Al crystals and reduces the undercooling needed for solidification to take place. Moreover, we present evidences that these Nb-based compounds prevent the growth of columnar crystals and permit to obtain, for the first time, fine and equiaxed crystals in directionally solidified Al-10Si braze alloy. As a consequence of the potent heterogeneous particles, the size of the α-Al crystals was found to be less dependent on the processing conditions, especially the thermal gradient. Finally, we also demonstrate that the enhanced nucleation leads to the refinement of secondary phases such as eutectic silicon and primary silicon particles. PMID:28008967

  8. Long-term reactive transport modelling of stabilized/solidified waste: from dynamic leaching tests to disposal scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Windt, Laurent de [Ecole des Mines de Paris, CG-Hydrodynamics and Reaction Group, 35 R. St-Honore, 77300 Fontainebleau (France)]. E-mail: laurent.dewindt@ensmp.fr; Badreddine, Rabia [INERIS, Direction des Risques Chroniques, Unite Dechets et Sites Pollues, Parc Technologique Alata BP 2, 60550 Verneuil-en-Halatte (France); Lagneau, Vincent [Ecole des Mines de Paris, CG-Hydrodynamics and Reaction Group, 35 R. St-Honore, 77300 Fontainebleau (France)

    2007-01-31

    Environmental impact assessment of hazardous waste disposal relies, among others, on standardized leaching tests characterized by a strong coupling between diffusion and chemical processes. In that respect, this study shows that reactive transport modelling is a useful tool to extrapolate laboratory results to site conditions characterized by lower solution/solid (L/S) ratios, site specific geometry, infiltration, etc. A cement solidified/stabilized (S/S) waste containing lead is investigated as a typical example. The reactive transport model developed in a previous study to simulate the initial state of the waste as well as laboratory batch and dynamic tests is first summarized. Using the same numerical code (HYTEC), this model is then integrated to a simplified waste disposal scenario assuming a defective cover and rain water infiltration. The coupled evolution of the S/S waste chemistry and the pollutant plume migration are modelled assessing the importance of the cracking state of the monolithic waste. The studied configurations correspond to an undamaged and fully sealed system, a few main fractures between undamaged monoliths and, finally, a dense crack-network in the monoliths. The model considers the potential effects of cracking, first the increase of rain water and carbon dioxide infiltration and, secondly, the increase of L/S ratio and reactive surfaces, using either explicit fracture representation or dual porosity approaches.

  9. High damping Al-Fe-Mo-Si/Zn-Al composites produced by rapidly solidified powder metallurgy process

    International Nuclear Information System (INIS)

    Li, P.Y.; Dai, S.L.; Chai, S.C.; Li, Y.R.

    2000-01-01

    The metallic materials commonly used in aircraft and aerospace fields, such as aluminum and titanium alloys, steels, etc., show extremely low damping capacity (usually of the order of or less than 10 -3 ). Thus, some problems related to vibration may emerge and influence the reliability, safety and life of airplanes, satellites, etc. It has been reported that almost two thirds of errors for rockets and satellites are related to vibration and noise. One effective way to solve these vibration-related problems is to adopt high damping metallic materials. Conventional high damping alloys exhibit damping capacity above 10 -2 , however, their densities are usually great than 5 x 10 3 kg m -3 , or their strengths are less than 200 MPa (for alloys based on dislocation damping), making them impossible to be applied to aircraft and aerospace areas. Recently, some low-density high-damping metal/metal composites based on aluminum and high damping alloys have been developed in Beijing Institute of Aeronautical Materials (BIAM) by the rapidly solidified power metallurgy process. This paper aims to report the properties of the composites based on a high temperature Al-Fe-Mo-Si alloy and a high damping Zn-Al alloy, and compare them with that of 2618-T61 alloy produced by the ingot metallurgy process

  10. Effect of Trace Ce on Microstructure and Properties of Near-rapidly Solidified Al-Zn-Mg-Cu Alloys

    Directory of Open Access Journals (Sweden)

    HUANG Gao-ren

    2018-03-01

    Full Text Available Through using DSC, XRD, SEM, EDS, static tensile test and other analysis methods of materials, the effect of trace Ce on microstructure and properties of near-rapidly solidified Al-Zn-Mg-Cu alloy was studied in order to find out rational homogenizing heat treatment process. The results show that Ce plays a role of refining grain and purifying molten alloy. The addition of Ce reduces dendritic spacing, refines the grain structures, eliminates dispersed shrinkage. The addition of Ce reduces the initial melting point of low melting eutectic phases by 3℃, under the same homogenization conditions. Trace Ce promotes the dissolution of low melting eutectic phases into the matrix, which improves the effect of homogenization. Homogenization temperatures of alloy A should be lower than 480℃and alloy B should be lower than 470℃; the addition of Ce decreases the homogenization temperature and improves the homogenization effect. The addition of Ce also greatly increases the tensile strength of the alloys.

  11. Mechanism of nucleation and growth of hydrogen porosity in solidifying A356 aluminum alloy: an analytical solution

    International Nuclear Information System (INIS)

    Li, K.-D.; Chang, Edward

    2004-01-01

    This study derives an analytical solution for the mechanism of nucleation and growth of hydrogen pore in the solidifying A356 aluminum alloy. A model of initial transient hydrogen redistribution in the growing dendritic grain is used to modify the lever rule for the mechanism of nucleation of pore. The model predicts the fraction of solid at nucleation, the temperature range of nucleation, the radius of hydrogen diffusion cell, and the supersaturation of hydrogen needed for nucleation. The role of solidus velocity in nucleation is explained. The parameters calculated from the model of nucleation are used for analyzing the mechanism of kinetic diffusion-controlled growth of pore, in which the mathematical transformations of variables are introduced. With the transformations, it is argued that the diffusion problem involving the liquid and solid phases during solidification could be treated as a classic problem of precipitation in the single-phase medium treated by Ham or Avrami. The analytical solution for the nucleation of pore is compared with the mechanism of macrosegregation. The predicted volume percent of porosity and radius of pore based on the mechanism of growth of pore is discussed with respect to the thermodynamic solution, the published experimental data, the numerical solutions, and the role of interdendritic fluid flow governed by Darcy's law

  12. Evolution of the microstructure and nanohardness of Ti-48 at.%Al alloy solidified under high pressure

    International Nuclear Information System (INIS)

    Wang, Hongwei; Zhu, Dongdong; Zou, Chunming; Wei, Zunjie

    2012-01-01

    Highlights: → The microstructure of Ti-48Al alloy changes under high pressure. → With increasing pressure, the amount of γ s phase decreases. → High pressure leads to the decreasing of lamellar spacing. → The nanohardness of lamellar structure increases with pressure. -- Abstract: In this work the microstructure and nanohardness of Ti-48 at.%Al alloy solidified under different pressures (normal pressure, 2 GPa, 4 GPa) were experimental investigated by using a tungsten-carbide six-anvil apparatus. The results indicate that high pressure does not change the phase constitution of Ti-48 at.%Al alloy. However, the microstructure changes under high pressure. With increasing pressure, the volume fraction of interdendritic γ (γ s ) phase decreases and Al concentration in lamellae increases. When the pressure is 4 GPa, there is only a little γ s embedded in lamellar structure. The volume fraction of γ s phase is approximately 17.0% for normal pressure, 8.73% for 2 GPa, 0.69% for 4 GPa. The lamellar spacings also decrease with pressure, which are 495 nm, 345 nm, 227 nm under normal pressure, 2 GPa, 4 GPa, respectively. The change in nanohardness was discussed based on the microstructural observations. It shows a certain increase of the nanohardness as the pressure increases from normal pressure to 4 GPa. When the pressure is 4 GPa, the nanohardness increases by 50.2% compared with that of normal pressure.

  13. Sensitive determination of cadmium using solidified floating organic drop microextraction-slotted quartz tube-flame atomic absorption spectroscopy.

    Science.gov (United States)

    Akkaya, Erhan; Chormey, Dotse Selali; Bakırdere, Sezgin

    2017-09-20

    In this study, solidified floating organic drop microextraction (SFODME) by 1-undecanol was combined with slotted quartz tube flame atomic absorption spectrometry (SQT-FAAS) for the determination of cadmium at trace levels. Formation of a complex with 4,4'-dimethyl-2,2'-bipyridine facilitated the extraction of cadmium from aqueous solutions. Several chemical variables were optimized in order to obtain high extraction outputs. Parameters such as concentration of the ligand, pH, and amount of buffer solution were optimized to enhance the formation of cadmium complex. The SFODME method was assisted by dispersion of extractor solvent into aqueous solutions using 2-propanol. Under the optimum extraction and instrumental conditions, the limit of detection and limit of quantitation values obtained for cadmium using the combined methods (SFODME-SQT-FAAS) were found to be 0.4 and 1.3 μg L -1 , respectively. Matrix effects on the method were also examined for tap water and wastewater, and spiked recovery results were found to be very satisfactory. Graphical Abstract SFODME-SQT-FAAS system for sensitive determination of cadmium.

  14. The influence of Si and V on the kinetics of phase transformation and microstructure of rapidly solidified Al-Fe-Zr alloys

    OpenAIRE

    Karpe B.; Kosec B.; Nagode A.; Bizjak M.

    2013-01-01

    The influence of Si and V on the precipitation kinetics of the rapidly solidified (RS) Al-Fe-Zr alloys is presented. Precipitation kinetics and microstructural development of RS Al-Fe-Zr alloys with Si or V addition have been investigated by the combination of four point electrical resistance measurement, optical microscopy, transmition electron microscopy (TEM) and scanning electron microscopy (SEM). For verification of the electrical resistivity measurement results differential scanni...

  15. Gravity and magnetic data across the Ghost Dance Fault in WT-2 Wash, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Oliver, H.W.; Sikora, R.F.

    1994-01-01

    Detailed gravity and ground magnetic data were obtained in September 1993 along a 4,650 ft-long profile across the Ghost Dance Fault system in WT-2 Wash. Gravity stations were established every 150 feet along the profile. Total-field magnetic measurements made initially every 50 ft along the profile, then remade every 20 ft through the fault zone. These new data are part of a geologic and geophysical study of the Ghost Dance Fault (GDF) which includes detailed geologic mapping, seismic reflection, and some drilling including geologic and geophysical logging. The Ghost Dance Fault is the only through-going fault that has been identified within the potential repository for high-level radioactive waste at Yucca Mountain, Nevada. Preliminary gravity results show a distinct decrease of 0.1 to 0.2 mGal over a 600-ft-wide zone to the east of and including the mapped fault. The gravity decrease probably marks a zone of brecciation. Another fault-offset located about 2,000 ft to the east of the GDF was detected by seismic reflection data and is also marked by a distinct gravity low. The ground magnetic data show a 200-ft-wide magnetic low of about 400 nT centered about 100 ft east of the Ghost Dance Fault. The magnetic low probably marks a zone of brecciation within the normally polarized Topopah Spring Tuff, the top of which is about 170 ft below the surface, and which is known from drilling to extend to a depth of about 1,700 ft. Three-component magnetometer logging in drill hole WT-2 located about 2,700 ft east of the Ghost Dance Fault shows that the Topopah Spring Tuff is strongly polarized magnetically in this area, so that fault brecciation of a vertical zone within the Tuff could provide an average negative magnetic contrast of the 4 Am -1 needed to produce the 400 nT low observed at the surface

  16. Microtexture formation of Ni99B1 alloys solidified on an ESL and an EML-a study based on the EBSP technique

    International Nuclear Information System (INIS)

    Li Mingjun; Ishikawa, Takehiko; Nagashio, Kosuke; Kuribayashi, Kazuhiko; Yoda, Shinichi

    2007-01-01

    We employed an electrostatic levitator (ESL) and an electromagnetic levitator (EML) to solidify Ni 99 B 1 (at.%) alloys at various undercoolings. The microstructures and microtextures were revealed by using the electron backscatter diffraction pattern (EBSP) technique in a scanning electron microscope. It is found that that no significant refinement can be identified at the low and medium undercooling regimes for the primary trunk in the sample solidified on the ESL, while the fragmentation of the secondary and even tertiary branches may take place to generate equiaxed grains. Further investigation by the EBSP reveals that neighboring grains have small misorientation angles, which may be ascribed to the absence of mechanical stirring from electromagnetic eddy current. A sharp contrast is that the samples solidified on the EML at low and medium undercoolings have refined equiaxed microstructures. The EBSP mapping reveals that the equiaxed grains yielded on the EML have a random distribution in crystallographic orientations among neighboring grains, indicating that electromagnetic stirring (EMS) induced by the electromagnetic field in the EML plays a vital role in promoting fragmentation and thus generating refined grains and random distribution in orientation. Regarding to the refined microstructure at high undercoolings, no significant difference arises in the samples processed between the EML and ESL

  17. A comparative EBSP study of microstructure and microtexture formation from undercooled Ni99B1 melts solidified on an electrostatic levitator and an electromagnetic levitator

    International Nuclear Information System (INIS)

    Li Mingjun; Ishikawa, Takehiko; Nagashio, Kosuke; Kuribayashi, Kazuhiko; Yoda, Shinichi

    2006-01-01

    Ni 99 B 1 alloys were solidified by containerless processing at various melt undercoolings on an electrostatic levitator (ESL) and an electromagnetic levitator (EML). A scanning electron microscope in combination with an electron backscatter diffraction pattern mapping technique was employed to reveal microstructures and microtextures formed on these two facilities. The microstructure consists of well-developed primary dendrites with coarse secondary arms in the alloys solidified on the ESL at low and medium undercooling levels, whereas equiaxed grains are yielded in alloys solidified on the EML at almost the same undercoolings. Further analysis indicates that the melt flow induced by the electromagnetic field in the EML may play a significant role in promoting fragmentation of primary dendrites in the mushy zone and thus resulting in equiaxed grains. In contrast, the primary dendrites in the alloy processed on the ESL can fully develop in the absence of melt flow. The fluid flow in the sample on the EML can rotate, move, and displace surviving fragments, yielding a random distribution of grain orientation and thus leading to a random microtexture at low and medium undercoolings. At high undercoolings, refined equiaxed grains can be obtained on both the ESL and the EML and the influence of melt flow on refinement seems negligible due to the enhanced driving force in capillarity and solute effects. A great number of coherent annealing twins are formed, making the pole figures more complex and random

  18. Microtexture formation of Ni{sub 99}B{sub 1} alloys solidified on an ESL and an EML-a study based on the EBSP technique

    Energy Technology Data Exchange (ETDEWEB)

    Li Mingjun [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)], E-Mail: li.mingjun@aist.go.jp; Ishikawa, Takehiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Nagashio, Kosuke [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Kuribayashi, Kazuhiko [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Yoda, Shinichi [Japan Aerospace Exploration Agency, Institute of Space and Astronautical Science, Tsukuba Space Center, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)

    2007-03-25

    We employed an electrostatic levitator (ESL) and an electromagnetic levitator (EML) to solidify Ni{sub 99}B{sub 1} (at.%) alloys at various undercoolings. The microstructures and microtextures were revealed by using the electron backscatter diffraction pattern (EBSP) technique in a scanning electron microscope. It is found that that no significant refinement can be identified at the low and medium undercooling regimes for the primary trunk in the sample solidified on the ESL, while the fragmentation of the secondary and even tertiary branches may take place to generate equiaxed grains. Further investigation by the EBSP reveals that neighboring grains have small misorientation angles, which may be ascribed to the absence of mechanical stirring from electromagnetic eddy current. A sharp contrast is that the samples solidified on the EML at low and medium undercoolings have refined equiaxed microstructures. The EBSP mapping reveals that the equiaxed grains yielded on the EML have a random distribution in crystallographic orientations among neighboring grains, indicating that electromagnetic stirring (EMS) induced by the electromagnetic field in the EML plays a vital role in promoting fragmentation and thus generating refined grains and random distribution in orientation. Regarding to the refined microstructure at high undercoolings, no significant difference arises in the samples processed between the EML and ESL.

  19. Microstructure formation and in situ phase identification from undercooled Co-61.8 at.% Si melts solidified on an electromagnetic levitator and an electrostatic levitator

    Energy Technology Data Exchange (ETDEWEB)

    Li Mingjun [National Institute of Advanced Industrial Science and Technology (AIST), Materials Research Institute for Sustainable Development, 2266-98 Shimo-Shidami, Moriyama, Nagoya, Aichi 463-8560 (Japan); Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Tsukuba Space Centre, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan)], E-mail: li.mingjun@aist.go.jp; Nagashio, Kosuke [Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Ishikawa, Takehiko [Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Tsukuba Space Centre, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Mizuno, Akitoshi; Adachi, Masayoshi; Watanabe, Masahito [Department of Physics, Gakushuin University, 1-5-1 Mejiro, Toshima, Tokyo 171-8588 (Japan); Yoda, Shinichi [Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Tsukuba Space Centre, ISS Science Project Office, 2-1-1 Sengen, Tsukuba, Ibaraki 305-8505 (Japan); Kuribayashi, Kazuhiko [Japan Aerospace Exploration Agency (JAXA), Institute of Space and Astronautical Science (ISAS), Sagamihara Campus, 3-1-1 Yoshinodai, Sagamihara, Kanagawa 229-8510 (Japan); Katayama, Yoshinori [Japan Atomic Energy Agency (JAEA), 1-1-1 Kouto, Mikazuki, Sayo, Hyogo 679-5148 (Japan)

    2008-06-15

    Co-61.8 at.% Si (CoSi-CoSi{sub 2}) eutectic alloys were solidified on an electromagnetic levitator (EML) and an electrostatic levitator (ESL) at different undercooling levels. The results indicated that there is only a single recalescence event at low undercooling with the CoSi intermetallic compound as primary phase, which is independent of processing facilities, on either an EML or an ESL. The microstructure, however, is strongly dependent on the processing facility. The interior melt flow behavior in the sphere solidified at the EML differs substantially from that at the ESL, thus yielding different microstructures. On high undercooling, double recalescence takes place regardless of levitation condition. In situ X-ray diffraction of alloys solidified on the EML demonstrates that the CoSi{sub 2} compound becomes the primary phase upon the first recalescence, and the CoSi intermetallic phase crystallizes during the second recalescence. In addition to phase identification, real-time diffraction patterns can also provide additional evidence of the fragmentation of the primary phase and the ripening feature in the subsequent cooling process in the semisolid state. The phase competition between the CoSi and CoSi{sub 2} compounds is discussed when considering the nucleation barrier. The low interfacial energy of the CoSi{sub 2} phase favors a preferential nucleation event over the CoSi phase, which also plays a critical role in non-reciprocity nucleation and thus yields a double recalescence profile at high undercooling.

  20. Examination of solidified and stabilized matrices as a result of solidification and stabilization process of arseniccontaining sludge with portland cement and lime

    Directory of Open Access Journals (Sweden)

    Tanapon Phenrat

    2004-02-01

    Full Text Available By solidification and stabilization (S/S with Portland cement and lime, it is possible to reduce arsenic concentration in leachate of the arsenic-containing sludge from arsenic removal process by coagulation with ferric chloride. From the initial arsenic concentration in leachate of unsolidified /unstabilized sludge which was around 20.75 mg/L, the arsenic concentrations in leachate of solidified/stabilized waste were reduced to 0.3, 0.58, 1.09, and 1.85 mg/L for the waste-to-binder ratios of 0.15, 0.25, 0.5, and 1, respectively, due tothe formation of insoluble calcium-arsenic compounds. To be more cost effective for the future, alternative uses of these S/S products were also assessed by measurement of compressive strength of the mortar specimens. It was found that the compressive strengths of these matrices were from 28 ksc to 461 ksc. In conclusion, considering compressive strength and leachability of the solidified matrices, some of these solidified/ stabilized products have potential to serve as an interlocking concrete paving block.

  1. Frequency of WT1 and 11p15 constitutional aberrations and phenotypic correlation in childhood Wilms tumour patients.

    Science.gov (United States)

    Segers, H; Kersseboom, R; Alders, M; Pieters, R; Wagner, A; van den Heuvel-Eibrink, M M

    2012-11-01

    In 9-17% of Wilms tumour patients a predisposing syndrome is present, in particular WT1-associated syndromes and overgrowth syndromes. Constitutional WT1 mutations or epigenetic changes on chromosome 11p15 have also been described in Wilms tumour patients without phenotypic abnormalities. Thus, the absence of phenotypic abnormalities does not exclude the presence of a genetic predisposition, suggesting that more Wilms tumour patients may have a constitutional abnormality. Therefore, we investigated the frequency of constitutional aberrations in combination with phenotype. Clinical genetic assessment, as well as molecular analysis of WT1 and locus 11p15 was offered to a single-centre cohort of 109 childhood Wilms tumour patients. Twelve patients (11%) had a WT1 aberration and eight patients (8%) had an 11p15 aberration. Of the 12 patients with a WT1 aberration, four had WAGR syndrome (Wilms tumor, aniridia, genitourinary malformations and mental retardation), one had Denys-Drash syndrome, four had genitourinary anomalies without other syndromic features and three had bilateral disease with stromal-predominant histology at young age without congenital anomalies. Of the eight patients with an 11p15 aberration, four had Beckwith-Wiedemann syndrome (BWS), two had minor features of BWS and two had no stigmata of BWS or hemihypertrophy. Constitutional WT1 or 11p15 aberrations are frequent in Wilms tumour patients and careful clinical assessment can identify the majority of these patients. Therefore, we would recommend offering clinical genetic counselling to all Wilms tumour patients, as well as molecular analysis to patients with clinical signs of a syndrome or with features that may indicate a constitutional WT1 or 11p15 aberration. Copyright © 2012 Elsevier Ltd. All rights reserved.

  2. Effects of concomitant temozolomide and radiation therapies on WT1-specific T-cells in malignant glioma

    International Nuclear Information System (INIS)

    Chiba, Yasuyoshi; Hashimoto, Naoya; Tsuboi, Akihiro

    2010-01-01

    Immunotherapy targeting the Wilms' tumour 1 gene product has been proven safe and effective for treating malignant glioma in a phase II clinical study. Currently, radiation/temozolomide therapy is the standard treatment with only modest benefit. Whether combining radiation/temozolomide therapy with WT1 immunotherapy will have a negating effect on immunotherapy is still controversial because of the significant lymphocytopaenia induced by the former therapy. To address this issue, we investigated the changes in frequency and number of WT1-specific T-cells in patients with malignant gliomas. Twenty-two patients with newly diagnosed malignant glioma who received standard radiation/temozolomide therapy were recruited for the study. Blood samples were collected before treatment and on the sixth week of therapy. The frequencies and numbers of lymphocytes, CD8 + T-cells, WT1-specific T-cells, regulatory T-cells, natural killer cells and natural killer T-cells were measured and analysed using T-tests. Analysis of the frequency of T lymphocytes and its subpopulation showed an increase in regulatory T-cells, but no significant change was noted in the populations of T-cells, WT1-specific T-cells, natural killer (NK) cells and natural killer T (NKT) cells. Reductions in the total numbers of T-cells, WT1-specific T-cells, NK cells and NKT cells were mainly a consequence of the decrease in the total lymphocyte count. Radiation/temozolomide therapy did not significantly affect the frequency of WT1-specific T-cells, suggesting that the combination with WT1 immunotherapy may be possible, although further assessment in the clinical setting is warranted. (author)

  3. Characterization of laser welds in Al-10 wt.%Si coated ferritic stainless steel

    International Nuclear Information System (INIS)

    Kong, Jong Pan; Park, Tae Jun; Kim, Jeong Kil; Uhm, Sang Ho; Woo, In Su; Lee, Jong Sub; Park, Bong Gyu; Kang, Chung Yun

    2011-01-01

    409L stainless steel hot-dipped with Al-10 wt.%Si was welded using CO 2 laser and the microstructure and hardness of the weld were investigated. When the specimen was welded with laser power of 5 kW and welding speed of 5 m/min, full-penetrated sound weld was obtained. With that specimen, the relationship between the microstructure and hardness of the weld was examined. The hardness of the weld was the highest in the fusion zone (FZ) and decreased to the base metal (BM) via heat affected zone (HAZ). The hardness of the HAZ near bond line was also higher than that near the base metal. The maximum hardness in the fusion zone could be explained by the existence of the precipitates, that is, TiN, Ti(C,N), Al 2 O 3 and Al 2 O 3 + TiN mixed compounds with the size of 500 nm, and solution strengthening due to the elements Al and Si dissolved from the coating layer to the fusion zone. There were subgrains within the HAZ and more in the area near the bond line. In addition, fine TiC particles with the size under 50 nm was precipitated in the sub-grain boundaries. The formation of sub-grain boundaries and the particles precipitated in the boundaries might contributed to the high hardness in the HAZ.

  4. Hydride redistribution and crack growth in Zr-2.5 wt.% Nb stressed in torsion

    International Nuclear Information System (INIS)

    Puls, M.P.; Rogowski, A.J.

    1980-11-01

    The effect of applied shear stresses on zirconium hydride solubility in a zirconium alloy was investigated. Recent studies have shown that zirconium hydride precipiates probably nucleate and grow by means of a shear transformation mechanism. It is postulated that these transformation shear strains can interact with applied shear stress gradients in the same way that the dilatational strains can interact with a dilatational stress gradient, providing a driving force for hydride accumulation, hydride embrittlement and crack propagation. To test this proposition, crack growth experiments were carried out under torsional loading conditions on hydrided, round notched bar specimens of cold-worked Zr-2.5 wt.% Nb cut from Pickering-type pressure tube material. Postmortem metallographic examination of the hydride distribution in these samples showed that, in many cases, the hydrides appeared to have reoriented in response to the applied shear stress and that hydride accumulation at the notch tip had occurred. However, except in a few cases, the rate of accumulation of reoriented hydrides at the notch tip due to applied shear stresses was much less than the rate due to corresponding applied uniaxial stresss. Moreover, the process in shear appears to be more sensitive to the inital hydride size. Attempts to elucidate the fracture mechanism by fractographic examination using scanning and replica transmission electron microscopy proved to be inconclusive because of smearing of the fracture face. (auth)

  5. Corrosion behavior of ferritic stainless steel with 15wt% chromium for the automobile exhaust system

    Science.gov (United States)

    Li, Hua-bing; Jiang, Zhou-hua; Feng, Hao; Zhu, Hong-chun; Sun, Bin-han; Li, Zhen

    2013-09-01

    The effect of chloride ion concentration, pH value, and grain size on the pitting corrosion resistance of a new ferritic stainless steel with 15wt% Cr was investigated using the anodic polarization method. The semiconducting properties of passive films with different chloride ion concentrations were performed using capacitance measurement and Mott-Schottky analysis methods. The aging precipitation and intergranular corrosion behavior were evaluated at 400-900°C. It is found that the pitting potential decreases when the grain size increases. With the increase in chloride ion concentration, the doping density and the flat-bland potential increase but the thickness of the space charge layer decreases. The pitting corrosion resistance increases rapidly with the decrease in pH value. Precipitants is identified as Nb(C,N) and NbC, rather than Cr-carbide. The intergranular corrosion is attributed to the synergistic effects of Nb(C,N) and NbC precipitates and Cr segregation adjacent to the precipitates.

  6. Development of rolled joints for zirconium-2.5 wt % niobium pressure tubes

    International Nuclear Information System (INIS)

    Madhusoodanan, K.; Sinha, R.K.; Samuel, K.A.; Joeman, V.

    1992-01-01

    Due to its higher strength and lower deuterium pick-up rate, as compared to the existing cold worked zircaloy-2 material, cold worked zirconium-2.5 wt% niobium (Zr-2.5%Nb) alloy is to be used as the pressure tube material in all forthcoming Indian PHWRs starting with KAPP-2. These pressure tubes, which carry the fuel bundles are to be joined to the S.S 403 end-fittings through rolled joints. Since the new pressure tubes have a lower wall thickness and higher room temperature yield stress, than zircaloy-2 tubes the design parameters of the rolled joint had to be developed afresh. Further, since Zr-2.5%Nb is susceptible to delayed hydride cracking, it is necessary to limit the residual stress near the rolled joint to a minimum. Since the high residual stress is due to the initial assembly clearance between the pressure tube and end-fitting, a modified rolled joint had to be developed, referred to as zero clearance rolled joint. This paper provides details of the work carried out at Reactor Engineering Division of Bhabha Atomic Research Centre, Bombay towards the development of the design of the rolled joint as well as the tooling and procedures required for achieving zero-clearance fit-ups at site. The requirements to be met by the Zr-2.5% Nb pressure tubes for achieving acceptable rolled joints are highlighted. (author). 5 refs., 6 figs., 3 tabs

  7. In-reactor creep of zirconium-2.5 wt% niobium at 570 K

    International Nuclear Information System (INIS)

    Coleman, C.E.; Causey, A.R.; Fidleris, V.

    1976-01-01

    The effect of fast neutron flux at 570 K on the creep rate of specimens of zirconium-2.5 wt% niobium alloy taken from tubes in various metallurgical conditions has been measured using both constant load tensile creep machines and bent-beam stress relaxation. Creep rates calculated from stress relaxation fit on the trend line for the constant load creep data. Between 114 MPa and 450 MPa the creep rate is proportional to neutron flux. The creep rate of specimens from the longitudinal direction is about twice that of specimens from the circumferential direction of a tube. This anisotropy in creep strength is attributed partly to crystallographic texture and partly to deformation substructure. Cold-work is detrimental to in-reactor creep strength; as-extruded material has higher creep strength. In cold-worked material at stresses below 100 MPa the stress exponent, n, is about 1; n gradually increases with stress being about 10 at 525 MPa and about 100 at 660 MPa. In laboratory tests, rupture ductility correlates inversely with n; the lower n the higher the ductility. In-reactor tests support this correlation thus pressure tubes in CANDU reactors, operating at 117 MPa where n approximately 1, should have good ductility. (Auth.)

  8. Influence of microstructure on the mechanical properties of a Zr-4.6 wt.% Al alloy

    International Nuclear Information System (INIS)

    Raman, V.; Mukhopadhyay, P.; Banerjee, S.

    1978-01-01

    The influence of microstructure on the room temperature mechanical properties of a Zr-4.6 wt.% Al alloy was investigated. Quenching from the beta phase produced a significant solid solution hardening. On aging the alloy at low temperatures for short periods aluminium rejection from the solid solution occurred and a fine dispersion of a metastable Zr 3 Al phase (DO 19 structure) formed. The strengthening caused by the presence of these ordered particles was found to more than compensate the softening brought about by decreasing supersaturation. The high strength corresponding to this structure could be explained in terms of the contributions from the coherency strains associated with and the state of order within the metastable particles. Aging at these temperatures for longer periods or at higher temperatures gave rise to a lamellar distribution of the α-zirconium (aluminium) and the equilibrium Zr 3 Al (Ll 2 structure) phases. The strength associated with this lamellar structure was found to be appreciably lower and to be strongly dependent on the interlamellar spacing. Investigations of the fracture surfaces showed that the modes of fracture associated with these different microstructures were different. An attempt was made to rationalize the observed strength properties in terms of existing theoretical models. (Auth.)

  9. Nb46, 5wt% Ti Eb-melting for AC and DC superconducting applications

    International Nuclear Information System (INIS)

    Bormio, C.; Ramos, M.J.; Pinatti, D.G.

    1990-01-01

    This paper reports on the superconductor alloy Nb46, 5wt % Ti which presents the best superconducting and mechanical properties for the systems Nb-Ti. The greatest difficulty in obtaining this alloy is related to the difference between the raw materials melting temperatures, which is about 700 degrees C. As a result the alloy homogeneity as well as Ti desired content, turn to be hard to control. The authors choose an electrode sandwich type, where Nb and Ti sheets are interposed. The electrode dimensions calculation is based on the Ti evaporation rate, energy balance and superficial tension of liquid titanium between Nb sheets. The ingots were electron beam melted. Herein, we present the following ingot results: Ti, intersticial and trace contents compared to international manufactures as well as its mechanical workability. This alloy will be used in NbTi wire production for AC and DC applications. The AC and DC wires are produced by coswaging and codrawing of NbTi bars and C u Ni-tubes for AC wires and Cu-tubes for DC wires. High area reductions of about 2 x 10 8 are reached without intermediate heat treatment, and they are essential since they are precursors of collective pinning centers, responsible for high critical current densities

  10. Solid solution in Al-4.5 wt% Cu produced by mechanical alloying

    International Nuclear Information System (INIS)

    Fogagnolo, J.B.; Amador, D.; Ruiz-Navas, E.M.; Torralba, J.M.

    2006-01-01

    Mechanical alloying has been used to produce oxide dispersion strengthened alloys, intermetallic compounds, aluminium alloys and to obtain nanostructured and amorphous materials, as well as to extend the solid solution limit. In this work, Al and Cu elemental powders were subjected to high-energy milling to produce Al-4.5 wt% Cu powder alloy. The powders obtained were characterized by scanning electron microscopy, X-ray diffraction (XRD) and differential scanning calorimetry (DSC), aiming to explore if the copper is present in solid solution or as small particles after high-energy milling. Related to the formation of a supersaturated solid solution, the results of scanning electron microscopy and X-ray diffraction are non-conclusive: the copper could be dispersed with a very small size, undetectable to both techniques. The Al 2 Cu precipitation at temperatures between 160 and 230 deg. C, verified by DSC and XRD analyses, substantiated that mechanical alloying had produced a supersaturated solid solution of copper in aluminium. The crystallite size as a function of milling time and annealing temperature was also determined by X-ray techniques

  11. Characterization of dispersion strengthened copper with 3wt%Al2O3 by mechanical alloying

    Directory of Open Access Journals (Sweden)

    Rajković Višeslava

    2004-01-01

    Full Text Available The copper matrix has been dispersion strengthened with 3wt.%Al2O3 by mechanical alloying. Commercial alumina powder with an average particle size of 0.75mm was used for alloying. The mechanical alloying process was performed in a planetary ball mill up to 20h in air. After milling all powders were treated in H2 at 4000C for 1h, and finally hot pressing was used for compaction (800oC, 3h, Ar. Structure observations revealed a lamellar structure (Al2O3 particles largely restricted to interlamellar planes between adjacent copper lamellae accompanied also by structure refinement. These structural changes were mostly completed in the early stage of milling, and retained after compaction. Micro hardness was found to progressively increase with milling time. So, after 5h of milling the micro hardness of the Cu+3twt%Al2O3 compact was 1540MPa, i.e. 2.5 times greater than for the as-received electrolytic copper powder (638MPa compacted under identical conditions, while after 20h of milling it was 2370 MPa. However after exposing the tested compact at 800oC up to 5h, the achieved hardening effect vanished.

  12. Porous anodic film formation on an Al-3.5 wt% Cu alloy

    Energy Technology Data Exchange (ETDEWEB)

    Paez, M.A.; Bustos, O.; Thompson, G.E.; Skeldon, P.; Shimizu, K.; Wood, G.C.

    2000-03-01

    Anodic film growth has been undertaken on an electropolished Al-3.5 wt % Cu alloy to determine the influence of copper in solid solution on the anodizing behavior. At the commencement of anodizing of the electropolished alloy, in the presence of interfacial enrichment of copper, Al{sup 3+} and Cu{sup 2+} ions egress and O{sup 2{minus}} ion ingress proceed; film growth occurs at the alloy/film interface though O{sup 2{minus}} ion ingress, with outwardly mobile Al{sup 3+} and Cu{sup 2+} ions ejected at the film/electrolyte interface, and field-assisted dissolution proceeding at the bases of pores. Oxidation of copper, in the presence of the enriched layer, is also associated with O{sub 2} gas generation, leading to development of oxygen-filled voids. As a result of significant pressures in the voids, film rupture proceeds, with electrolyte access to the alloy, dissolution of the enriched interfacial layer and re-anodizing. The consequence of such processes in the development of anodic films of increased porosity and reduced efficiency of film formation compared with anodizing of superpure aluminum under similar conditions.

  13. The coarsening process of Ge precipitates in an Al-4 wt.% Ge alloy

    Energy Technology Data Exchange (ETDEWEB)

    Deaf, G.H

    2004-05-01

    In this paper the results of a quantitative transmission electron microscopy (TEM) investigation of the precipitation process of Ge in an Al-4 wt.% Ge alloy are described. Two crystallographic orientation relationships between the irregular germanium precipitate and aluminum matrix were found to be [1 0 0]{sub Ge} || [1 1 0]{sub Al} and [1 1 4]{sub Ge} || [1 0 0]{sub Al}. The irregular germanium precipitates formed on [0 0 1]{sub Al} habit planes. The origin of the irregular shape is due to the existence of a highly anisotropic interfacial energy as well as in an isotropic growth rate along <1 1 0>{sub A1} directions. Particles sizes were determined for variety of isothermal ageing times at 348, 423 and 523 K. The coarsening of the different morphologies of Ge precipitates was found to obey Ostwald ripening kinetics. The TEM results showed that the coarsening of irregular particles was due to the interfacial coalescence between these particles. Nine different morphologies have been distinguished in the form of (i) irregular particles, (ii) spheres, (iii) hexagonal plates, (iv) rods, (v) triangular plates, (vi) laths, (vii) small tetrahedra, (viii) rectangular plates, and (ix) Lamellae shape.

  14. Air pollution control systems in WtE units: An overview

    Energy Technology Data Exchange (ETDEWEB)

    Vehlow, J., E-mail: juergen.vehlow@partner.kit.edu

    2015-03-15

    Highlights: • The paper describes in brief terms the development of gas cleaning in waste incineration. • The main technologies for pollutant removal are described including their basic mechanisms. • Their respective efficiencies and their application are discussed. • A cautious outlook regarding future developments is made. - Abstract: All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made.

  15. Hydrogen absorption kinetics in powdered V + 80 wt.% LaNi5 composite

    International Nuclear Information System (INIS)

    Kumar, Sanjay; Tirpude, Amit; Taxak, Manju; Krishnamurthy, Nagaiyar

    2013-01-01

    Highlights: •Vanadium prevents the pulverization of LaNi 5 . •H absorption capacity LaNi 5 –V composite is higher than LaNi 5 . •H absorption kinetics of LaNi 5 –V composite is relatively faster than V and LaNi 5 . •Fermi energy level of LaNi 5 –V composite lowered by vanadium addition. -- Abstract: The hydrogen absorption behavior of V + 80 wt.% LaNi 5 composite, LaNi 5 and V has been investigated. The LaNi 5 –V composite was prepared by high energy ball-milling technique using high pure vanadium and LaNi 5 powder. Lattice expansion of the composite has been observed in X-ray analysis which indicates the solid solution formation. Presence of free V and traces of V 2 O 5 phase were also observed in the composite. The hydrogen absorption capacity and absorption kinetics of the composite showed improvement as compared to LaNi 5 . The improved kinetics of the composite has been co-related to the change in lattices parameter, Fermi energy level and catalytic property of vanadium. Integrity of the composite has found to be effective even after 20 numbers of hydriding and dehydriding cycles due to the presence of vanadium

  16. Microstructure and mechanical properties of an extruded Mg-8Bi-1Al-1Zn (wt%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Shuaiju [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Yu, Hui, E-mail: yuhuidavid@gmail.com [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); Materials Commercialization Center, Korea Institute of Materials Science, Changwon 51508 (Korea, Republic of); Zhang, Huixing [Mechanical and Material School, Tianjin Sino-German University of Applied Sciences, Tianjin 300350 (China); Cui, Hongwei [School of Materials Science and Engineering, Shangdong University of Technology, Zibo 255049 (China); Park, Sung Hyuk [School of Materials Science and Engineering, Kyungpook National University, Daegu 702701 (Korea, Republic of); Zhao, Weiming [School of Materials Science and Engineering, Hebei University of Technology, Tianjin 300130 (China); You, Bong Sun [Materials Commercialization Center, Korea Institute of Materials Science, Changwon 51508 (Korea, Republic of)

    2017-04-06

    In this study, the microstructural evolution and mechanical properties of a newly developed rare earth free Mg-8Bi-1Al-1Zn (BAZ811, in wt%) alloy were investigated and compared with those of a commercial AZ31 alloy. The as-extruded BAZ811 alloy with much finer grain size shows more homogeneous dynamical recrystallized (DRXed) microstructure and weaker basal texture than those of AZ31 alloy. In addition, compared with bimodal structure AZ31 alloy containing only relatively coarse and sparse Al{sub 8}Mn{sub 5} phases, the coexistence of strip-like fragmented Mg{sub 3}Bi{sub 2} precipitate and nano-size Mg{sub 3}Bi{sub 2} particles in the microstructure was observed in BAZ811 alloy. Moreover, the BAZ811 alloy exhibits a tensile yield stress of 291 MPa, an ultimate tensile strength of 331 MPa, an elongation to failure of 14.6% as well as a reduction in yield asymmetry, which is mainly attributed to the combined effects of grain refinement and micro-scale broken Mg{sub 3}Bi{sub 2} particles together with nano-scale spherical Mg{sub 3}Bi{sub 2} precipitates. The strain hardening behavior of both BAZ811 and AZ31 alloys were also discussed in terms of microstructure variation.

  17. Thermal treatment of solid residues from WtE units: A review

    Energy Technology Data Exchange (ETDEWEB)

    Lindberg, Daniel, E-mail: daniel.lindberg@abo.fi; Molin, Camilla, E-mail: camilla.molin@abo.fi; Hupa, Mikko, E-mail: mikko.hupa@abo.fi

    2015-03-15

    Highlights: • We review the thermal treatment methods for ashes and residues from WtE plants. • We review the results from extensive laboratory work on vitrification, melting and vaporization of ash. • We analyze the results from the extensive patent literature on thermal treatment. • We review industrial concepts for thermal treatment of ash. - Abstract: Thermal treatment methods of bottom ash, fly ash and various types of APC (air pollution control) residues from waste-to-energy plants can be used to obtain environmentally stable material. The thermal treatment processes are meant to reduce the leachability of harmful residue constituents, destroy toxic organic compounds, reduce residue volume, and produce material suitable for utilization. Fly ash and APC residues often have high levels of soluble salts, particularly chlorides, metals such as cadmium, lead, copper and zinc, and trace levels of organic pollutants such as dioxins and furans. Different thermal treatment methods can be used to either decompose or stabilize harmful elements and compounds in the ash, or separate them from the ash to get a material that can be safely stored or used as products or raw materials. In the present paper, thermal treatment methods, such as sintering, vitrification, and melting have been reviewed. In addition to a review of the scientific literature, a survey has been made of the extensive patent literature in the field.

  18. Analysis of irradiated U-7wt%Mo dispersion fuel microstructures using automated image processing

    Energy Technology Data Exchange (ETDEWEB)

    Collette, R. [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); King, J., E-mail: kingjc@mines.edu [Colorado School of Mines, Nuclear Science and Engineering Program, 1500 Illinois St, Golden, CO 80401 (United States); Buesch, C. [Oregon State University, 1500 SW Jefferson St., Corvallis, OR 97331 (United States); Keiser, D.D.; Williams, W.; Miller, B.D.; Schulthess, J. [Nuclear Fuels and Materials Division, Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

    2016-07-15

    The High Performance Research Reactor Fuel Development (HPPRFD) program is responsible for developing low enriched uranium (LEU) fuel substitutes for high performance reactors fueled with highly enriched uranium (HEU) that have not yet been converted to LEU. The uranium-molybdenum (U-Mo) fuel system was selected for this effort. In this study, fission gas pore segmentation was performed on U-7wt%Mo dispersion fuel samples at three separate fission densities using an automated image processing interface developed in MATLAB. Pore size distributions were attained that showed both expected and unexpected fission gas behavior. In general, it proved challenging to identify any dominant trends when comparing fission bubble data across samples from different fuel plates due to varying compositions and fabrication techniques. The results exhibited fair agreement with the fission density vs. porosity correlation developed by the Russian reactor conversion program. - Highlights: • Automated image processing is used to extract fission gas bubble data from irradiated U−Mo fuel samples. • Verification and validation tests are performed to ensure the algorithm's accuracy. • Fission bubble parameters are predictably difficult to compare across samples of varying compositions. • The 2-D results suggest the need for more homogenized fuel sampling in future studies. • The results also demonstrate the value of 3-D reconstruction techniques.

  19. Thermal treatment of solid residues from WtE units: A review

    International Nuclear Information System (INIS)

    Lindberg, Daniel; Molin, Camilla; Hupa, Mikko

    2015-01-01

    Highlights: • We review the thermal treatment methods for ashes and residues from WtE plants. • We review the results from extensive laboratory work on vitrification, melting and vaporization of ash. • We analyze the results from the extensive patent literature on thermal treatment. • We review industrial concepts for thermal treatment of ash. - Abstract: Thermal treatment methods of bottom ash, fly ash and various types of APC (air pollution control) residues from waste-to-energy plants can be used to obtain environmentally stable material. The thermal treatment processes are meant to reduce the leachability of harmful residue constituents, destroy toxic organic compounds, reduce residue volume, and produce material suitable for utilization. Fly ash and APC residues often have high levels of soluble salts, particularly chlorides, metals such as cadmium, lead, copper and zinc, and trace levels of organic pollutants such as dioxins and furans. Different thermal treatment methods can be used to either decompose or stabilize harmful elements and compounds in the ash, or separate them from the ash to get a material that can be safely stored or used as products or raw materials. In the present paper, thermal treatment methods, such as sintering, vitrification, and melting have been reviewed. In addition to a review of the scientific literature, a survey has been made of the extensive patent literature in the field

  20. Precipitation under cyclic strain in solution-treated Al4wt%Cu I: mechanical behavior

    Energy Technology Data Exchange (ETDEWEB)

    Farrow, Adam M [Los Alamos National Laboratory; Laird, Campbell [UNIV OF PENNSYLVANIA

    2008-01-01

    Solution-treated AL-4wt%Cu was strain-cycled at ambient temperature and above, and the precipitation and deformation behaviors investigated by TEM. Anomalously rapid growth of precipitates appears to have been facilitated by a vacancy super-saturation generated by cyclic strain and the presence of a continually refreshed dislocation density to provide heterogeneous nucleation sites. Texture effects as characterized by Orientation Imaging Microscopy appear to be responsible for latent hardening in specimens tested at room temperature, with increasing temperatures leading to a gradual hardening throughout life due to precipitation. Specimens exhibiting rapid precipitation hardening appear to show a greater effect of texture due to the increased stress required to cut precipitates in specimens machined from rolled plate at an angle corresponding to a lower average Schmid factor. The accelerated formation of grain boundary precipitates appears to be partially responsible for rapid inter-granular fatigue failure at elevated temperatures, producing fatigue striations and ductile dimples coexistent on the fracture surface.

  1. Air pollution control systems in WtE units: An overview

    International Nuclear Information System (INIS)

    Vehlow, J.

    2015-01-01

    Highlights: • The paper describes in brief terms the development of gas cleaning in waste incineration. • The main technologies for pollutant removal are described including their basic mechanisms. • Their respective efficiencies and their application are discussed. • A cautious outlook regarding future developments is made. - Abstract: All WtE (waste-to-energy) plants, based on combustion or other thermal processes, need an efficient gas cleaning for compliance with legislative air emission standards. The development of gas cleaning technologies started along with environment protection regulations in the late 1960s. Modern APC (air pollution control) systems comprise multiple stages for the removal of fly ashes, inorganic and organic gases, heavy metals, and dioxins from the flue gas. The main technologies and devices used for abatement of the various pollutants are described and their basic principles, their peculiarities, and their application are discussed. Few systems for cleaning of synthesis gas from waste gasification plants are included. Examples of APC designs in full scale plants are shown and cautious prospects for the future development of APC systems are made

  2. Effects of Ce concentrations on ignition temperature and surface tension of Mg-9wt.%Al alloy

    Directory of Open Access Journals (Sweden)

    Deng Zhenghua

    2013-03-01

    Full Text Available Magnesium alloys are well known for their excellent properties, but the potential issues with oxidation and burning during melting and casting largely limit its industrial applications. The addition of Ce in magnesium alloys can significantly raise ignition-proof performance and change the structure of the oxide film on the surface of the molten metal as well as the surface tension values. Surface tension is an important physical parameter of the metal melts, and it plays an important role in the formation of surface oxide film. In this present work, the ignition temperature and the surface tension of Mg-9wt.%Al alloy with different Ce concentrations were studied. Surface tensions was measured using the maximum bubble pressure method (MBPM. Ignition temperature was measured using NiCr-NiSi type thermocouples and was monitored and recorded via a WXT-604 desk recording device. The results show that the ignition point of Mg-9wt.%Al alloy can be effectively elevated by adding Ce. The ignition temperature reaches its highest point of 720 ℃ when the addition of Ce is 1wt.%. The surface tension of the molten Mg-9wt.%Al alloy decreases exponentially with the increase of Ce addition at the same temperature. Similarly, the experiment also shows that the surface tension of Mg-9wt.%Al alloy decreases exponentially with the increase of temperature.

  3. Classification of different kinds of pesticide residues on lettuce based on fluorescence spectra and WT-BCC-SVM algorithm

    Science.gov (United States)

    Zhou, Xin; Jun, Sun; Zhang, Bing; Jun, Wu

    2017-07-01

    In order to improve the reliability of the spectrum feature extracted by wavelet transform, a method combining wavelet transform (WT) with bacterial colony chemotaxis algorithm and support vector machine (BCC-SVM) algorithm (WT-BCC-SVM) was proposed in this paper. Besides, we aimed to identify different kinds of pesticide residues on lettuce leaves in a novel and rapid non-destructive way by using fluorescence spectra technology. The fluorescence spectral data of 150 lettuce leaf samples of five different kinds of pesticide residues on the surface of lettuce were obtained using Cary Eclipse fluorescence spectrometer. Standard normalized variable detrending (SNV detrending), Savitzky-Golay coupled with Standard normalized variable detrending (SG-SNV detrending) were used to preprocess the raw spectra, respectively. Bacterial colony chemotaxis combined with support vector machine (BCC-SVM) and support vector machine (SVM) classification models were established based on full spectra (FS) and wavelet transform characteristics (WTC), respectively. Moreover, WTC were selected by WT. The results showed that the accuracy of training set, calibration set and the prediction set of the best optimal classification model (SG-SNV detrending-WT-BCC-SVM) were 100%, 98% and 93.33%, respectively. In addition, the results indicated that it was feasible to use WT-BCC-SVM to establish diagnostic model of different kinds of pesticide residues on lettuce leaves.

  4. Microstructure, Mechanical Properties and Corrosion Behavior of Porous Mg-6 wt.% Zn Scaffolds for Bone Tissue Engineering

    Science.gov (United States)

    Yan, Yang; Kang, Yijun; Li, Ding; Yu, Kun; Xiao, Tao; Wang, Qiyuan; Deng, Youwen; Fang, Hongjie; Jiang, Dayue; Zhang, Yu

    2018-03-01

    Porous Mg-based scaffolds have been extensively researched as biodegradable implants due to their attractive biological and excellent mechanical properties. In this study, porous Mg-6 wt.% Zn scaffolds were prepared by powder metallurgy using ammonium bicarbonate particles as space-holder particles. The effects of space-holder particle content on the microstructure, mechanical properties and corrosion resistance of the Mg-6 wt.% Zn scaffolds were studied. The mean porosity and pore size of the open-cellular scaffolds were within the range 6.7-52.2% and 32.3-384.2 µm, respectively. Slight oxidation was observed at the grain boundaries and on the pore walls. The Mg-6 wt.% Zn scaffolds were shown to possess mechanical properties comparable with those of natural bone and had variable in vitro degradation rates. Increased content of space-holder particles negatively affected the mechanical behavior and corrosion resistance of the Mg-6 wt.% Zn scaffolds, especially when higher than 20%. These results suggest that porous Mg-6 wt.% Zn scaffolds are promising materials for application in bone tissue engineering.

  5. Differential evolution of a CXCR4-using HIV-1 strain in CCR5wt/wt and CCR5∆32/∆32 hosts revealed by longitudinal deep sequencing and phylogenetic reconstruction.

    Science.gov (United States)

    Le, Anh Q; Taylor, Jeremy; Dong, Winnie; McCloskey, Rosemary; Woods, Conan; Danroth, Ryan; Hayashi, Kanna; Milloy, M-J; Poon, Art F Y; Brumme, Zabrina L

    2015-12-03

    Rare individuals homozygous for a naturally-occurring 32 base pair deletion in the CCR5 gene (CCR5∆32/∆32) are resistant to infection by CCR5-using ("R5") HIV-1 strains but remain susceptible to less common CXCR4-using ("X4") strains. The evolutionary dynamics of X4 infections however, remain incompletely understood. We identified two individuals, one CCR5wt/wt and one CCR5∆32/∆32, within the Vancouver Injection Drug Users Study who were infected with a genetically similar X4 HIV-1 strain. While early-stage plasma viral loads were comparable in the two individuals (~4.5-5 log10 HIV-1 RNA copies/ml), CD4 counts in the CCR5wt/wt individual reached a nadir of 250 cells/mm(3) in the CCR5∆32/∆32 individual. Ancestral phylogenetic reconstructions using longitudinal envelope-V3 deep sequences suggested that both individuals were infected by a single transmitted/founder (T/F) X4 virus that differed at only one V3 site (codon 24). While substantial within-host HIV-1 V3 diversification was observed in plasma and PBMC in both individuals, the CCR5wt/wt individual's HIV-1 population gradually reverted from 100% X4 to ~60% R5 over ~4 years whereas the CCR5∆32/∆32 individual's remained consistently X4. Our observations illuminate early dynamics of X4 HIV-1 infections and underscore the influence of CCR5 genotype on HIV-1 V3 evolution.

  6. Corrosion behavior of Mg–5Al based magnesium alloy with 1 wt.% Sn, Mn and Zn additions in 3.5 wt.% NaCl solution

    Directory of Open Access Journals (Sweden)

    Nguyen Dang Nam

    2014-06-01

    Full Text Available The corrosion properties of four Mg–5Al alloys with M-alloying elements (tin, manganese and zinc in a 3.5 wt.% NaCl solution were examined using electrochemical tests and surface analyses. The electrochemical results indicated that the addition of 1 wt.% M metal decreased the corrosion rate and hydrogen evolution rate of the Mg–5Al specimens. Moreover, the addition of 1Zn resulted in having the best corrosion resistance due to the interaction of Zn oxide with Mg and Al oxides which acted as a corrosion barrier.

  7. Effect of iron addition on the work-hardening characteristics of Al-16 wt%Ag alloy

    International Nuclear Information System (INIS)

    Abd El-Salam, F.; Mahmoud, M.A.; Abd El-Khalek, A.M.; Nada, R.H.

    2002-01-01

    The effect of pre-aging time (up to 120 min) and temperatures (428-498 K) on the stress-strain characteristics of Al-16 wt%Ag and Al-16 wt%Ag-0.28 wt%Fe alloys was investigated at different deformation temperatures in the range 353-413 K. The tensile parameters measured for both alloys showed general increase with increasing pre-aging time at 428 and 458 K, while the samples pre-aged at 498 K showed initial softening up to pre-aging time of 60 min followed by increased hardening for longer pre-aging times. The Fe-free samples were generally harder than the ternary samples. The activation energy of the fracture mechanism in both alloys was around 28 kJ/mol

  8. Microstructural study on gamma phase stability in U-9 wt% Mo alloy system

    International Nuclear Information System (INIS)

    Saify, M.T.; Jha, S.K.; Hussain, M.M.; Singh, R.P.; Neogy, S.; Srivastava, D.; Dey, G.K.

    2009-01-01

    Uranium exists in three polymorphic forms viz., orthorhombic α phase - stable up to 667 deg C, tetragonal β phase - stable between 667 deg C and 771 deg C and bcc γ phase - stable above 771 deg C. When alloying of uranium is done, the alloying additions alter the temperature ranges over which the α, β and γ phases are stable. In addition, they frequently retard the rates at which phase transformations occur. As a result, a number of metastable phases can be obtained in uranium alloys. It has been well known among reactor designers that a pure uranium metal is not suitable for power reactor fuel mainly because of (i) phase changes occurring at lower temperatures and (ii) poor irradiation behavior of α phase. γ phase uranium alloys containing small amount of another metal to stabilize the γ-U solid solution provides good prospects in this respect. U-Mo alloy is one of the prospective materials for low enrichment uranium fuel with high U loading because a solid solution of Mo in the γ-U phase possesses acceptable irradiation and mechanical properties and is formed over a wide range of Mo concentration. In the present work vacuum induction melted and cast U-9 wt% Mo alloy was subjected to different thermo mechanical processing to investigate the stability of the γ phase. The as cast alloy was rolled at 550 deg C and then homogenized at 1000 deg C in the γ phase field for 24 hours followed by (i) water quenching and (ii) furnace cooling to generate two different starting conditions. Two of the water-quenched samples were aged at 500 deg C for 5 days and 14 days and one as-rolled sample was aged at 500 deg C for 5 days. The as-cast, as-rolled, homogenized and aged samples were subjected to optical microscopy and X-ray Diffraction (XRD) investigations. All the samples were also subjected to microhardness measurements. The as cast sample contained predominantly the gamma phase along with inclusions. After homogenizing the alloy at 1000 deg C and quenching in

  9. Cooling thermal parameters and microstructure features of directionally solidified ternary Sn–Bi–(Cu,Ag) solder alloys

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Bismarck L., E-mail: bismarck_luiz@yahoo.com.br [Department of Materials Engineering, Federal University of São Carlos, UFSCar, 13565-905 São Carlos, SP (Brazil); Garcia, Amauri [Department of Manufacturing and Materials Engineering, University of Campinas, UNICAMP, 13083-860 Campinas, SP (Brazil); Spinelli, José E. [Department of Materials Engineering, Federal University of São Carlos, UFSCar, 13565-905 São Carlos, SP (Brazil)

    2016-04-15

    Low temperature soldering technology encompasses Sn–Bi based alloys as reference materials for joints since such alloys may be molten at temperatures less than 180 °C. Despite the relatively high strength of these alloys, segregation problems and low ductility are recognized as potential disadvantages. Thus, for low-temperature applications, Bi–Sn eutectic or near-eutectic compositions with or without additions of alloying elements are considered interesting possibilities. In this context, additions of third elements such as Cu and Ag may be an alternative in order to reach sounder solder joints. The length scale of the phases and their proportions are known to be the most important factors affecting the final wear, mechanical and corrosions properties of ternary Sn–Bi–(Cu,Ag) alloys. In spite of this promising outlook, studies emphasizing interrelations of microstructure features and solidification thermal parameters regarding these multicomponent alloys are rare in the literature. In the present investigation Sn–Bi–(Cu,Ag) alloys were directionally solidified (DS) under transient heat flow conditions. A complete characterization is performed including experimental cooling thermal parameters, segregation (XRF), optical and scanning electron microscopies, X-ray diffraction (XRD) and length scale of the microstructural phases. Experimental growth laws relating dendritic spacings to solidification thermal parameters have been proposed with emphasis on the effects of Ag and Cu. The theoretical predictions of the Rappaz-Boettinger model are shown to be slightly above the experimental scatter of secondary dendritic arm spacings for both ternary Sn–Bi–Cu and Sn–Bi–Ag alloys examined. - Highlights: • Dendritic growth prevailed for the ternary Sn–Bi–Cu and Sn–Bi–Ag solder alloys. • Bi precipitates within Sn-rich dendrites were shown to be unevenly distributed. • Morphology and preferential region for the Ag{sub 3}Sn growth depend on Ag

  10. Electrochemical properties of rapidly solidified Si-Ti-Ni(-Cu) base anode for Li-ion rechargeable batteries

    Science.gov (United States)

    Kwon, Hye Jin; Sohn, Keun Yong; Park, Won-Wook

    2013-11-01

    In this study, rapidly solidified Si-Ti-Ni-Cu alloys have been investigated as high capacity anodes for Li-ion secondary batteries. To obtain nano-sized Si particles dispersed in the inactive matrix, the alloy ribbons were fabricated using the melt spinning process. The thin ribbons were pulverized using ball-milling to make a fine powder of ˜ 4 µm average size. Coin-cell assembly was carried out under an argon gas in a glove box, in which pure lithium was used as a counter-electrode. The cells were cycled using the galvanostatic method in the potential range of 0.01 V and 1.5 V vs. Li/Li+. The microstructure and morphology were examined using an x-ray diffractometer, Field-Emission Scanning Electron Microscopy and High Resolution Transmission Electron Microscopy. Among the anode alloys, the Si70Ti15Ni15 electrodes had the highest discharge capacity (974.1 mAh/g) after the 50th cycle, and the Si60Ti16Ni16Cu8 electrode showed the best coulombic efficiency of ˜95.9% in cyclic behavior. It was revealed that the Si7Ni4Ti4 crystal phase coexisting with an amorphous phase, could more efficiently act as a buffer layer than the fully crystallized Si7Ni4Ti4 phase. Consequently, the electrochemical properties of the anode materials pronouncedly improved when the nano-sized primary Si particle was dispersed in the inactive Si7Ni4Ti4-based matrix mixed with an amorphous structure.

  11. Formulation development and in vitro evaluation of solidified self-microemulsion in the form of tablet containing atorvastatin calcium.

    Science.gov (United States)

    Ali, Kazi Asraf; Mukherjee, Biswajit; Bandyopadhyay, Amal Kumar

    2013-11-01

    The objective of our present study was to prepare solid self-microemulsion in the form of tablet of a poorly water soluble drug, Atorvastatin calcium (ATNC) to increase the solubility, dissolution rate, and minimize the hazards experienced from liquid emulsions. Self-microemulsifying ATNC tablet was formulated mainly by using self-emulsifying base, solidifying agent silicon dioxide and sodium starch glycolate as tablet disintegrant. Self-emulsifying base containing Transcutol P, Gelucire 44/14, and Lutrol F68 with their ratios in the formulation, were best selected by solubility study and ternary phase diagram in different vehicles. Particle size of microemulsion from tablet, physical parameters of the tablet and drug content has been checked. In vitro drug release rate has been carried out in phosphate buffer medium (pH 6.8). Physicochemical characterization of the drug in the optimized formulation has been performed to check drug-excipient incompatibility, if any. Average particle diameter of the emulsions formed from the tablet was found to be below 100 nm in case of formulation F4 and F5, which indicated microemulsions has been formed. In vitro drug release from the formulations F3, F4, and F5 was found to be >90%, indicated the enhancement of solubility of ATNC compared to parent drug. Differential thermal analysis (DTA), Powder X-ray Diffraction (X-RD) and Fourier transform infra red (FTIR) study proved the identity of the drug in the optimized formulation. The tablet form of self-microemulsifying (SME) drug delivery is good for solubility enhancement.

  12. Valence electron structure analysis of the cubic silicide intermetallics in rapidly solidified Al-Fe-V-Si alloy

    International Nuclear Information System (INIS)

    Wang, J.Q.; Qian, C.F.; Zhang, B.J.; Tseng, M.K.; Xiong, S.W.

    1996-01-01

    The application of rapid solidification for the development of elevated temperature aluminum alloys has resulted in the emergence of several alloys based on the Al-Fe alloy system. Of particular interest are Al-Fe-V-Si alloys which have excellent room temperature and high temperature mechanical properties. In a pioneering study, Skinner et al. showed the stabilization of the cubic phase in ternary Al-Fe-Si alloy by the addition of a quaternary element, vanadium. The evolution of the microstructure in these alloys both during rapid solidification and subsequent processing is of crucial importance. Kim has demonstrated that the composition of the silicide phase in rapidly solidified Al-Fe-V-Si alloy is very close to Al 12 (Fe,V) 3 Si with the body centered cubic (bcc) structure. The structure is closely related to that of quasicrystals.In view of the structural features and the relationship between the α 12 and α 13 phases, the researching emphasis should firstly be put on the α 12 phase. In this paper the authors analyzed the α -(AlFeSi)(α 12 -type) phase from the angle of atomic valence electron structure other than the traditional methods of obtaining the diffraction spots of the phase. Several pieces of information were obtained about the hybrid levels and bond natures of every kind of atom in the α -(AlFeSi) phase. Finally the authors explained the phenomenon which V atom can substitute for Fe atom in the α 12 phase and improve the thermal stability of the phase in Al-Fe-V-Si alloy

  13. Incorporating an extended dendritic growth model into the CAFE model for rapidly solidified non-dilute alloys

    International Nuclear Information System (INIS)

    Ma, Jie; Wang, Bo; Zhao, Shunli; Wu, Guangxin; Zhang, Jieyu; Yang, Zhiliang

    2016-01-01

    We have extended the dendritic growth model first proposed by Boettinger, Coriell and Trivedi (here termed EBCT) for microstructure simulations of rapidly solidified non-dilute alloys. The temperature-dependent distribution coefficient, obtained from calculations of phase equilibria, and the continuous growth model (CGM) were adopted in the present EBCT model to describe the solute trapping behaviors. The temperature dependence of the physical properties, which were not used in previous dendritic growth models, were also considered in the present EBCT model. These extensions allow the present EBCT model to be used for microstructure simulations of non-dilute alloys. The comparison of the present EBCT model with the BCT model proves that the considerations of the distribution coefficient and physical properties are necessary for microstructure simulations, especially for small particles with high undercoolings. Finally, the EBCT model was incorporated into the cellular automaton-finite element (CAFE) model to simulate microstructures of gas-atomized ASP30 high speed steel particles that were then compared with experimental results. Both the simulated and experimental results reveal that a columnar dendritic microstructure preferentially forms in small particles and an equiaxed microstructure forms otherwise. The applications of the present EBCT model provide a convenient way to predict the microstructure of non-dilute alloys. - Highlights: • A dendritic growth model was developed considering non-equilibrium distribution coefficient. • The physical properties with temperature dependence were considered in the extended model. • The extended model can be used to non-dilute alloys and the extensions are necessary in small particles. • Microstructure of ASP30 steel was investigated using the present model and verified by experiment.

  14. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material.

    Science.gov (United States)

    Gu, X N; Li, X L; Zhou, W R; Cheng, Y; Zheng, Y F

    2010-06-01

    Rapidly solidified (RS) Mg–3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s(-1), 30 m s(-1) and 45 m s(-1) with the as-cast Mg–3Ca alloy ingot as a raw material. The RS45 Mg–3Ca alloy ribbon showed a much more fine grain size feature (approximately 200–500 nm) in comparison to the coarse grain size (50–100 μm)of the original as-cast Mg–3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg–3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds(1.43 mm yr(-1) for RS15, 0.94 mm yr(-1) for RS30 and 0.36 mm yr(-1) for RS45). The RS Mg–3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg–3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg–3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells,whereas the as-cast Mg–3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg–3Ca alloy ribbons than that of the as-cast Mg–3Ca alloy ingot.

  15. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X N; Zhou, W R; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Li, X L [Center for Biomedical Materials and Engineering, Harbin Engineering University, Harbin 150001 (China); Cheng, Y, E-mail: yfzheng@pku.edu.c [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China)

    2010-06-01

    Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s{sup -1}, 30 m s{sup -1} and 45 m s{sup -1}) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 {mu}m) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr{sup -1} for RS15, 0.94 mm yr{sup -1} for RS30 and 0.36 mm yr{sup -1} for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

  16. Microstructure, biocorrosion and cytotoxicity evaluations of rapid solidified Mg-3Ca alloy ribbons as a biodegradable material

    International Nuclear Information System (INIS)

    Gu, X N; Zhou, W R; Zheng, Y F; Li, X L; Cheng, Y

    2010-01-01

    Rapidly solidified (RS) Mg-3Ca alloy ribbons were prepared by the melt-spinning technique at different wheel rotating speeds (15 m s -1 , 30 m s -1 and 45 m s -1 ) with the as-cast Mg-3Ca alloy ingot as a raw material. The RS45 Mg-3Ca alloy ribbon showed a much more fine grain size feature (approximately 200-500 nm) in comparison to the coarse grain size (50-100 μm) of the original as-cast Mg-3Ca alloy ingot. The corrosion electrochemical tests in simulated body fluid indicated that the corrosion rate of the as-cast Mg-3Ca alloy was strongly reduced by the RS procedure and tended to be further decreased with increasing wheel rotating speeds (1.43 mm yr -1 for RS15, 0.94 mm yr -1 for RS30 and 0.36 mm yr -1 for RS45). The RS Mg-3Ca alloy ribbons showed more uniform corrosion morphology compared with the as-cast Mg-3Ca alloy after polarization. The cytotoxicity evaluation revealed that the three experimental as-spun Mg-3Ca alloy ribbon extracts did not induce toxicity to the L-929 cells, whereas the as-cast Mg-3Ca alloy ingot extract did. The L-929 cells showed more improved adhesion on the surfaces of the three as-spun Mg-3Ca alloy ribbons than that of the as-cast Mg-3Ca alloy ingot.

  17. Effect of a high magnetic field on the microstructures in directionally solidified Zn–Cu peritectic alloys

    International Nuclear Information System (INIS)

    Li, Xi; Gagnoud, Annie; Wang, Jiang; Li, Xiaolong; Fautrelle, Yves; Ren, Zhongming; Lu, Xionggang; Reinhart, Guillaume; Nguyen-Thi, Henri

    2014-01-01

    The effect of an axial high magnetic field on the microstructures in directionally solidified Zn–Cu peritectic alloys was investigated. The experimental results indicated that the magnetic field induced the destabilization of the liquid–solid interface and the formation of a band-like structure. The magnetic field also caused the disruption of the columnar η-Zn and ε-Zn 5 Cu dendrites. As the applied magnetic field increased, the columnar-to-equiaxed transition occurred, and the size of the equiaxed grains gradually decreased. The magnetic effects, the magnetic moment and the thermoelectric magnetic effects during the directional solidification of Zn–Cu peritectic alloys under an axial magnetic field were studied. Regular ε-Zn 5 Cu hexagons appeared on the transverse section of the sample fabricated with a high magnetic field (i.e. 16 T). In addition, electron backscatter diffraction analysis revealed that the 〈0 0 0 1〉-crystal direction of the Zn 5 Cu crystal is not only its easy magnetization direction but also its preferred growth direction. The thermoelectric magnetic effects were numerically simulated. The results indicated that a thermoelectric magnetic force acts on the solid near the liquid–solid interface and increases linearly with an increase in the magnetic field. As the effect of the magnetic moment arising from the magnetic crystalline anisotropy is eliminated, the thermoelectric magnetic effect has a substantial effect on the solidification structure. Therefore, the destabilization of the liquid–solid interface and the disruption of the dendrites during directional solidification under the magnetic field are primarily due to the thermoelectric magnetic force acting on the solid

  18. Incorporating an extended dendritic growth model into the CAFE model for rapidly solidified non-dilute alloys

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Jie; Wang, Bo [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhao, Shunli [Research Institute, Baoshan Iron & Steel Co., Ltd, Shanghai 201900 (China); Wu, Guangxin [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Zhang, Jieyu, E-mail: zjy6162@staff.shu.edu.cn [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China); Yang, Zhiliang [State Key Laboratory of Advanced Special Steel, Shanghai University, Shanghai 200072 (China); Shanghai Engineering Technology Research Center of Special Casting, Shanghai 201605 (China)

    2016-05-25

    We have extended the dendritic growth model first proposed by Boettinger, Coriell and Trivedi (here termed EBCT) for microstructure simulations of rapidly solidified non-dilute alloys. The temperature-dependent distribution coefficient, obtained from calculations of phase equilibria, and the continuous growth model (CGM) were adopted in the present EBCT model to describe the solute trapping behaviors. The temperature dependence of the physical properties, which were not used in previous dendritic growth models, were also considered in the present EBCT model. These extensions allow the present EBCT model to be used for microstructure simulations of non-dilute alloys. The comparison of the present EBCT model with the BCT model proves that the considerations of the distribution coefficient and physical properties are necessary for microstructure simulations, especially for small particles with high undercoolings. Finally, the EBCT model was incorporated into the cellular automaton-finite element (CAFE) model to simulate microstructures of gas-atomized ASP30 high speed steel particles that were then compared with experimental results. Both the simulated and experimental results reveal that a columnar dendritic microstructure preferentially forms in small particles and an equiaxed microstructure forms otherwise. The applications of the present EBCT model provide a convenient way to predict the microstructure of non-dilute alloys. - Highlights: • A dendritic growth model was developed considering non-equilibrium distribution coefficient. • The physical properties with temperature dependence were considered in the extended model. • The extended model can be used to non-dilute alloys and the extensions are necessary in small particles. • Microstructure of ASP30 steel was investigated using the present model and verified by experiment.

  19. Modification and aging precipitation behavior of hypereutectic Al-21wt.%Si alloy treated by P+Ce combination

    Directory of Open Access Journals (Sweden)

    Liu Pei

    2014-11-01

    Full Text Available In the present study, the tested hypereutectic Al-21wt.%Si alloys were prepared by modifying the melt using different proportions of P and Ce, and then applying T6 heat treatment. The modification effects and mechanism of P+Ce complex modifier on the Si phase of hypereutectic Al-21wt.%Si alloy were studied, and the aging precipitation behavior after modification was characterized by means of tensile strength measurement, OM, SEM and TEM analysis. The results show that the massive primary silicon phase particles are significantly refined after modification, while the needle-like eutectic silicon crystals become fibrous and short. It was found that the mechanism of phosphorus modification on the primary silicon can be attributed to heterogeneous nucleation of AlP, while the modification mechanism of Ce can be explained by adsorbing-twinning theory. In the aged microstructure of the modified hypereutectic Al-21wt.%Si alloy, there existed some strengthening phases such as Al4Cu9, Al2Cu, AlCu3, and Al57Mn12. The P+Ce complex modifier not only affected the size of primary silicon and eutectic silicon, but also the aging behavior of alloys under the heat treatment process. When Al-21wt.%Si alloy was modified using 0.08%wt.P + 0.6wt.% Ce, the aging precipitates were dispersed uniformly in the alloy, and its mechanical properties at room and elevated temperatures are optimized (Rm = 287.6 MPa at RT, Rm = 210 MPa at 300 ℃.

  20. Tensile properties of strip casting 6.5 wt% Si steel at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Li, Hao-Ze, E-mail: lhzqq83@163.com; Liu, Zhen-Yu, E-mail: zyliu@mail.neu.edu.cn

    2015-07-15

    Tensile behaviors of strip casting 6.5 wt% Si steel are tested at elevated temperatures ranging from 300 °C to 800 °C. A detailed study of the morphology of the fracture surface and the ordered phase at each deforming temperature is carried out by a scanning electron microscope and a transmission electron microscope. The results show that the deforming temperature rather than the ordered degree determines the tensile properties. As the deforming temperature increases, the stress level in the whole deforming stage continually decreases, whereas the elongation gradually increases. The ductile–brittle transition occurs around 350 °C. The elongation of 2% at 300 °C rapidly increases up to 16.4% at 350 °C and the corresponding fracture mode transforms from the complete cleavage fracture to the mixture of the very limited cleavage fracture, intergranular dimple fracture and the dimple fracture. Serrated flow is observed at 350 °C and 400 °C probably due to the occurrence of dynamic strain aging. Due to the gradually weakened grain boundary cohesion with the deforming temperature increasing, intergranular dimple pattern dominates the fracture surface at 600 °C and the elongation slowly increases from 16.4% at 350 °C to 22.8% at 600 °C. At 700 °C and 800 °C, the much more enhanced dynamic recovery, the substantially decreased stress levels which contribute to the inhibition of the intergranular dimple fracture, the much lower content of the B2 ordered phase at 700 °C, and the completely disordered state at 800 °C give rise to the dramatically improved elongations of 88.8% and 130.8%, respectively.

  1. Theory and practice of corrosion related to ashes and deposits in a WtE boiler.

    Science.gov (United States)

    Verbinnen, Bram; De Greef, Johan; Van Caneghem, Jo

    2018-03-01

    Corrosion of heat-exchanging components is one of the main operational problems in Waste-to-Energy plants, limiting the electrical efficiency that can be reached. Corrosion is mainly related to the devolatilization and/or formation of chlorides, sulphates and mixtures thereof on the heat-exchanging surfaces. Theoretical considerations on this corrosion were already put forward in literature, but this paper now for the first time combines theory with a large scale sampling campaign of several Waste-to-Energy plants. Based on the outcome of elemental and mineralogical analysis, the distribution of Cl and S in ashes sampled throughout the plant during normal operation is explained. Cl concentrations are high (15-20%) in the first empty pass, decrease in the second and third empty pass, but increase again in the convective part, whereas the S concentrations show an inverse behavior, with the highest concentrations (30%) observed in the second and third empty pass. Sampling of deposits on specific places where corrosion possibly occurred, gives a better insight in the mechanisms related to corrosion phenomena in real-scale WtE plants and provides practical evidence for some phenomena that were only assumed on the basis of theory or lab scale experiments before. More specific, it confirms the role of oxygen content, temperatures in the different stages of the boiler, the presence of polysulphates, Pb and Zb, and the concentrations of HCl and SO 2 in the flue gas for different types of boiler corrosion. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. WT-BIRD. Bird collision monitoring system for multi-megawatt wind turbines

    Energy Technology Data Exchange (ETDEWEB)

    Wiggelinkhuizen, E.J.; Rademakers, L.W.M.M.; Barhorst, S.A.M. [ECN Wind Energy, Petten (Netherlands); Den Boon, H.J. [E-Connection Project, Bunnik (Netherlands); Dirksen, S. [Bureau Waardenburg, Culemborg (Netherlands)

    2007-05-15

    A new method for detection and registration of bird collisions has been developed that is suitable for continuous remote operation in both onshore and offshore wind farms. The characteristic sound of a collision is detected by sensors in the blades, which triggers the storage of video registrations and sends an alert message to the operator. A prototype has been tested successfully on a Nordex N80/2.5MW turbine at ECN's Wind turbine Test park Wieringermeer. Compared to other methods employed so far this monitoring system will reduce the uncertainty in the number of birds killed by collisions with wind turbines. Further, the system enables the operator to identify species and to study the collision mechanisms. It has been found that this system can also be used for monitoring of other events in order to save costs for inspection and repair after incidents. For offshore wind farms, the WT-Bird system is currently the only alternative to count the number of bird collisions. Functional tests with tennis balls that were shot against rotating blades showed that the majority of the impacts were detected. The flight track of these dummies and the collision events were clearly visible on the video registrations. During the monitoring period of about one year two bird collisions were detected. The video recordings confirmed that a collision took place and showed that the location of both collisions was near the blade root, which resulted that in both cases the bird was not (immediately) killed. Therefore no corpses could be found beneath the turbine after these events. Also during the rest of the monitoring period no corpses were found beneath the turbine.

  3. Hyperfine interactions and structural features of Fe–44Co–6Mo (wt.%) nanostructured powders

    International Nuclear Information System (INIS)

    Moumeni, Hayet; Nemamcha, Abderrafik; Alleg, Safia; Grenèche, Jean Marc

    2013-01-01

    Nanocrystalline Fe–44Co–6Mo (wt.%) powders have been prepared by high-energy ball milling from elemental Fe, Co and Mo pure powders in a P7 planetary ball mill. The obtained powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Mössbauer spectrometry techniques. The influence of milling process and Mo substitution for Co in equiatomic FeCo have been examined in order to study structural evolution and formation mechanism of nanostructured Fe(CoMo) solid solution. XRD results show the formation of a BCC Fe(CoMo) solid solution (a = 0.2874 nm) where unmixed nanocrystalline Mo with a BCC structure is embedded. Disordered Fe(CoMo) solid solution is characterized by a broad hyperfine magnetic field distribution with two regions centered at B 1 = 35.0 T and B 2 = 30.7 T, respectively, attributed to disordered Fe(Co) solid solution and CoMo enriched environments. Prolonged milling and Mo addition cause the decrease of average hyperfine magnetic field while the average isomer shift remains nearly constant. - Highlights: ► BCC nanostructured Fe(CoMo) solid solution is prepared by milling of Fe, Co and Mo. ► Formation mechanism: Co diffusion into Fe lattice and Mo dissolution in Fe(Co). ► Crystallite size of Fe(CoMo) solid solution reaches 11 nm after 24 h of milling. ► Mössbauer analysis reveals 3 components: high field, enriched Co and low field

  4. Hyperfine interactions and structural features of Fe–44Co–6Mo (wt.%) nanostructured powders

    Energy Technology Data Exchange (ETDEWEB)

    Moumeni, Hayet, E-mail: hmoumeni@yahoo.fr [Laboratoire de Chimie Computationnelle et Nanostructures, Département des Sciences de la Matière, Faculté des Mathématiques et de l' Informatique et des Sciences de la Matière, Université 08 Mai 1945 - Guelma, B.P. 401, Guelma 24000 (Algeria); Nemamcha, Abderrafik [Laboratoire d' Analyses Industrielles et Génie des Matériaux, Faculté des Sciences et de la Technologie, Université 08 Mai 1945 - Guelma, B.P. 401, Guelma 24000 (Algeria); Alleg, Safia [Laboratoire de Magnétisme et de Spectroscopie des Solides, Département de Physique, Faculté des Sciences, Université de Annaba, B.P. 12, Annaba 23000 (Algeria); Grenèche, Jean Marc [Laboratoire de Physique de l' Etat Condensé, UMR CNRS 6087, Institut de Recherche en Ingénierie Moléculaire et Matériaux Fonctionnels IRIM2F, FR CNRS 2575, Université du Maine, 72085 Le Mans Cedex 9 (France)

    2013-02-15

    Nanocrystalline Fe–44Co–6Mo (wt.%) powders have been prepared by high-energy ball milling from elemental Fe, Co and Mo pure powders in a P7 planetary ball mill. The obtained powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Mössbauer spectrometry techniques. The influence of milling process and Mo substitution for Co in equiatomic FeCo have been examined in order to study structural evolution and formation mechanism of nanostructured Fe(CoMo) solid solution. XRD results show the formation of a BCC Fe(CoMo) solid solution (a = 0.2874 nm) where unmixed nanocrystalline Mo with a BCC structure is embedded. Disordered Fe(CoMo) solid solution is characterized by a broad hyperfine magnetic field distribution with two regions centered at B{sub 1} = 35.0 T and B{sub 2} = 30.7 T, respectively, attributed to disordered Fe(Co) solid solution and CoMo enriched environments. Prolonged milling and Mo addition cause the decrease of average hyperfine magnetic field while the average isomer shift remains nearly constant. - Highlights: ► BCC nanostructured Fe(CoMo) solid solution is prepared by milling of Fe, Co and Mo. ► Formation mechanism: Co diffusion into Fe lattice and Mo dissolution in Fe(Co). ► Crystallite size of Fe(CoMo) solid solution reaches 11 nm after 24 h of milling. ► Mössbauer analysis reveals 3 components: high field, enriched Co and low field.

  5. Phase-field simulation of peritectic solidification closely coupled with directional solidification experiments in an Al-36 wt% Ni alloy

    International Nuclear Information System (INIS)

    Siquieri, R; Emmerich, H; Doernberg, E; Schmid-Fetzer, R

    2009-01-01

    In this work we present experimental and theoretical investigations of the directional solidification of Al-36 wt% Ni alloy. A phase-field approach (Folch and Plapp 2005 Phys. Rev. E 72 011602) is coupled with the CALPHAD (calculation of phase diagrams) method to be able to simulate directional solidification of Al-Ni alloy including the peritectic phase Al 3 Ni. The model approach is calibrated by systematic comparison to microstructures grown under controlled conditions in directional solidification experiments. To illustrate the efficiency of the model it is employed to investigate the effect of temperature gradient on the microstructure evolution of Al-36 wt% Ni during solidification.

  6. Prompt neutron decay constant for the Oak Ridge Research Reactor with 20 wt % 235U enriched fuel

    International Nuclear Information System (INIS)

    Ragan, G.E.; Mihalczo, J.T.

    1986-01-01

    This paper describes measurements of the prompt neutron decay constant at delayed criticality for the Oak Ridge Research Reactor (ORR) using 20 wt % 235 U enriched fuel and compares these measurements with similar measurements using 93.2 wt % 235 U enriched fuel. This reactor parameter is of interest because it affects the transient behavior of the reactor in prompt criticality accident situations. This experiment is part of a program to investigate the differences in the performance of research reactors fueled with highly enriched and low enriched uranium. The prompt neutron decay constants were obtained using noise analysis measurement techniques for a core with newly fabricated, unirradiated fuel elements

  7. Influence of ZnO nano-particles addition on thermal analysis, microstructure evolution and tensile behavior of Sn–5.0 wt% Sb–0.5 wt% Cu lead-free solder alloy

    Energy Technology Data Exchange (ETDEWEB)

    Fouda, A.N., E-mail: alynabieh@yahoo.com [Physics Department, Faculty of Science, Suez-Canal University, 41522 Ismailia (Egypt); Eid, E.A., E-mail: dr_eid_hti@yahoo.com [Basic Science Department, Higher Technological Institute, 44629 10th of Ramadan City (Egypt)

    2015-04-24

    Sn–5 wt%Sb–0.5 wt%Cu (plain SSC505) and Sn–5 wt%Sb–0.5 wt%Cu–0.5 wt% ZnO (SSC-ZnO) composite solder alloys have been studied. The variation in thermal behavior, microstructure and tensile characteristics associated with mixing of 0.5 wt% ZnO nano-metric particles to plain SSC505 solder were investigated. A slight increment in the melting temperature [ΔT{sub m}=0.89 °C] was recorded using differential scanning calorimetry (DSC) after addition of ZnO. X-Ray diffraction (XRD) analysis confirmed the existence of β-Sn, SbSn and Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) beside some of ZnO planes in SSC-ZnO composite solder. Field emission scanning electronic microscope (FE-SEM) investigation of SSC-ZnO composite solder revealed a homogenous uniform distribution, size refinement of IMCs and β-Sn grains. Addition of ZnO nano-metric particles into the plain SSC505 enhanced the yield stress σ{sub YS} by ~12% and improved the ultimate tensile strength σ{sub UTS} by ~13%. In addition, adding ZnO nano-metric particles was found to be effective for reducing ductility by ~43% of the plain solder due to the refinement of β-Sn grains within SSC-ZnO composite solder. - Highlights: • Melting point of SSC505-ZnO composite solder is slightly increased by 0.89 {sup ο}C compared with the plain SSC505 solder. • XRD and EDX analysis reflect the presence of SbSn, Cu{sub 6}Sn{sub 5} IMCs. • EF-SEM images of SSC-ZnO composite solder revealed homogenous uniform distribution of β-Sn grains and fine IMC particles. • A detectable improvement in the Young modulus, ultimate tensile strength and yield strength were observed after addition of 0.5 wt% ZnO nano-metric particles.

  8. Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter

    Science.gov (United States)

    1993-01-01

    Pratt & Whitney Advanced Ducted Propulsor (ADP) Engine Test in 40x80ft w.t.: Engineers Peter Zell (left) and Dr Clifton Horne (right) are shown preparing a laser light sheet for a flow visualization test. Shown standing in the nacelle of the ADP is John Girvin, senior test engineer for Pratt & Whitney.

  9. Effect of Reinforcement Content and Technological Parameters on the Properties of Cu-4 wt.% Ni-TiC Composites

    Science.gov (United States)

    Jha, Pushkar; Gautam, R. K.; Tyagi, Rajnesh

    2017-10-01

    The present study deals with the synthesis and investigation of microstructure, density, and hardness behavior of Cu-4 wt.% Ni-TiC metal matrix composites, produced by high-energy ball milling, followed by compaction and sintering. Matrix of Cu-4 wt.% Ni was used, and different weight percentages (0, 2, 4, 6, and 8) of TiC particles were added. The uniform distribution of TiC particles in the matrix alloy was confirmed by characterizing these composite powders by using scanning electron microscope, energy-dispersive spectroscopy, and x-ray diffraction. Both the density and the hardness of the composite containing 4 wt.% TiC were found to be the highest. The density was found to decrease with increasing TiC content beyond 4 wt.%, and it has been attributed to the agglomeration of TiC particles leading to the formation of pores when added in relatively larger amounts. The compressibility behaviors of the milled powders were studied by using Panelli and Ambrosio Filho equation.

  10. On the underlying micromechanisms in time-dependent anelasticity in Al-(1 wt%)Cu thin films

    NARCIS (Netherlands)

    Bergers, L.I.J.C.; Hoefnagels, J.P.M.; Geers, M.G.D.

    2017-01-01

    This paper reveals potential micro mechanisms underlying time-dependent anelasticity observed in Al-(1 wt%)Cu thin films. The analyzed deformation mechanisms involve dislocation motion and interaction with solute diffusion, grain boundaries and precipitates. In order to investigate the role of these

  11. Influence of high-energy ion implantation on the microstructure of Sn - 9,8 wt. % Zn alloy

    International Nuclear Information System (INIS)

    Gusakova, O.V.

    2016-01-01

    The results of investigation of influence of Xe ion implantation on the microstructure of Sn - 9,8 wt. % Zn alloy are represented/ Analysis of the experimental results shows that the high-energy ion implantation of Xe causes a change in the particle size of zinc. (authors)

  12. Correlation study on waist circumference-triglyceride (WT) index and coronary artery scores in patients with coronary heart disease.

    Science.gov (United States)

    Yang, R-F; Liu, X-Y; Lin, Z; Zhang, G

    2015-01-01

    Coronary disease is analyzed through common lipid profiles, but these analyses fail to account for residual risk due to abdominal weight and elevated TG levels. We aimed to investigate the relationship between the waist circumference × triglyceride index (WT index) and the Coronary Artery Score (CAS) in patients with coronary heart disease. 346 patients in our Cardiology Department were recruited from September 2007 to August 2011 and divided into two groups according to whether the patients presented with metabolic syndrome. We performed coronary angiography using the standard Judkins method. The severity of coronary artery stenosis and the CAS were calculated and analyzed with a computerized quantitative analysis system. The signs index, which includes the body mass index (BMI), waist circumference, hip circumference, waist-hip-ratio, and waist-height-ratio, the blood glucose and blood lipid index of all the patients were collected and used to calculate the WT index (waist circumference x triglyceride index. We performed a correlative analysis with age, gender, body mass index, blood glucose and blood lipid, blood pressure and other risk indicators of all patients as the dependent variables and the CAS as the independent variable. We show that the CAS is positively correlated to the WT index. Several lipid profiles and waist circumference were significantly associated with the CAS. The WT index is correlated to the CAS and is a good predictor for the development of coronary artery disease; it can be applied in the clinic for early intervention in populations at risk for coronary heart disease.

  13. THE EFFECT OF RARE EARTH ELEMENTS ON Cr PRECIPITATIONS IN A Cu-0.8WT%Cr ALLOY

    Directory of Open Access Journals (Sweden)

    Gewang Shuai

    2011-05-01

    Full Text Available The microstructural evolution of Cu-based alloys during aging was studied using a quantitative metallographic method. Samples were cut from ingots of Cu-0.8wt%Cr and Cu-0.8wt%Cr-RE alloys. These were solution treated at 1000 ºC for 1.5h and subsequently quenched in water, then separately aged at 480 ºC for different durations. The microstructures were observed by optical microscope, and the characteristic geometric parameters of precipitated Cr phase, including volume fraction VV, face density NA, mean diameter and roundness, were measured. These data provided more details about the process of aging. The results showed that precipitation of Cr phase occurred in the form of particles during aging. Rare earth elements promoted the precipitation of Cr phase and dispersed Cr particles. The phenomenon of overaging came earlier in Cu-Cr-RE than in Cu-Cr. In the present work, the optimal aging time at 480 ºC was 2 hrs for the Cu-0.8wt%Cr-RE alloy and 3 hours for the Cu-0.8wt%Cr alloy.

  14. 20 CFR 645.215 - What must a WtW operating entity that serves noncustodial parent participants do?

    Science.gov (United States)

    2010-04-01

    ... and children who may be at risk of domestic violence, the operating entity must consult with domestic violence prevention and intervention organizations in the development of its WtW project serving... school, (B) Earning a general equivalency degree, or (C) Participating in other education directly...

  15. Automatic Artifact Removal in EEG of Normal and Demented Individuals Using ICA–WT during Working Memory Tasks

    Directory of Open Access Journals (Sweden)

    Noor Kamal Al-Qazzaz

    2017-06-01

    Full Text Available Characterizing dementia is a global challenge in supporting personalized health care. The electroencephalogram (EEG is a promising tool to support the diagnosis and evaluation of abnormalities in the human brain. The EEG sensors record the brain activity directly with excellent time resolution. In this study, EEG sensor with 19 electrodes were used to test the background activities of the brains of five vascular dementia (VaD, 15 stroke-related patients with mild cognitive impairment (MCI, and 15 healthy subjects during a working memory (WM task. The objective of this study is twofold. First, it aims to enhance the recorded EEG signals using a novel technique that combines automatic independent component analysis (AICA and wavelet transform (WT, that is, the AICA–WT technique; second, it aims to extract and investigate the spectral features that characterize the post-stroke dementia patients compared to the control subjects. The proposed AICA–WT technique is a four-stage approach. In the first stage, the independent components (ICs were estimated. In the second stage, three-step artifact identification metrics were applied to detect the artifactual components. The components identified as artifacts were marked as critical and denoised through DWT in the third stage. In the fourth stage, the corrected ICs were reconstructed to obtain artifact-free EEG signals. The performance of the proposed AICA–WT technique was compared with those of two other techniques based on AICA and WT denoising methods using cross-correlation X C o r r and peak signal to noise ratio ( P S N R (ANOVA, p ˂ 0.05. The AICA–WT technique exhibited the best artifact removal performance. The assumption that there would be a deceleration of EEG dominant frequencies in VaD and MCI patients compared with control subjects was assessed with AICA–WT (ANOVA, p ˂ 0.05. Therefore, this study may provide information on post-stroke dementia particularly VaD and stroke

  16. Can T1 w/T2 w ratio be used as a myelin-specific measure in subcortical structures? Comparisons between FSE-based T1 w/T2 w ratios, GRASE-based T1 w/T2 w ratios and multi-echo GRASE-based myelin water fractions.

    Science.gov (United States)

    Uddin, Md Nasir; Figley, Teresa D; Marrie, Ruth Ann; Figley, Chase R

    2018-03-01

    Given the growing popularity of T 1 -weighted/T 2 -weighted (T 1 w/T 2 w) ratio measurements, the objective of the current study was to evaluate the concordance between T 1 w/T 2 w ratios obtained using conventional fast spin echo (FSE) versus combined gradient and spin echo (GRASE) sequences for T 2 w image acquisition, and to compare the resulting T 1 w/T 2 w ratios with histologically validated myelin water fraction (MWF) measurements in several subcortical brain structures. In order to compare these measurements across a relatively wide range of myelin concentrations, whole-brain T 1 w magnetization prepared rapid acquisition gradient echo (MPRAGE), T 2 w FSE and three-dimensional multi-echo GRASE data were acquired from 10 participants with multiple sclerosis at 3 T. Then, after high-dimensional, non-linear warping, region of interest (ROI) analyses were performed to compare T 1 w/T 2 w ratios and MWF estimates (across participants and brain regions) in 11 bilateral white matter (WM) and four bilateral subcortical grey matter (SGM) structures extracted from the JHU_MNI_SS 'Eve' atlas. Although the GRASE sequence systematically underestimated T 1 w/T 2 w values compared to the FSE sequence (revealed by Bland-Altman and mountain plots), linear regressions across participants and ROIs revealed consistently high correlations between the two methods (r 2 = 0.62 for all ROIs, r 2 = 0.62 for WM structures and r 2 = 0.73 for SGM structures). However, correlations between either FSE-based or GRASE-based T 1 w/T 2 w ratios and MWFs were extremely low in WM structures (FSE-based, r 2 = 0.000020; GRASE-based, r 2 = 0.0014), low across all ROIs (FSE-based, r 2 = 0.053; GRASE-based, r 2 = 0.029) and moderate in SGM structures (FSE-based, r 2 = 0.20; GRASE-based, r 2 = 0.17). Overall, our findings indicated a high degree of correlation (but not equivalence) between FSE-based and GRASE-based T 1 w/T 2 w ratios, and low correlations between T 1 w/T 2 w ratios and MWFs. This

  17. Influence of Nb content on grain size and mechanical properties of 18 wt% Cr ferritic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Y. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Mao, W.M., E-mail: weiminmao@263.net [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Chen, Y.J. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Jing, J.; Cheng, M. [Taizhou Xinyu Precision Manufacture Company Limited, Jiangyan 225500, Jiangsu (China)

    2016-11-20

    The influence of Nb contents between 0.20 and 1.20 wt% on the grain size and mechanical properties of 18 wt% Cr ferritic stainless steel produced by investment casting was investigated. The average grain sizes of the three steels decreased apparently with increasing Nb content mainly due to the increasing number of pre-existing oxides formed at higher temperature, which were more likely to be the nuclei of heterogeneous nucleation. The thermodynamic analysis of Nb(C,N) formation was in conformity to the experimental result that the Nb(C,N) precipitates became larger with increasing Nb content. The as-cast specimen with the smallest grain size of steel C had the worse tensile strength and elongation in comparison with the as-cast specimens of steels A and B, mostly owing to the catenarian and dendritic Nb(C,N) particles distributed densely at the grain boundaries. The mechanical properties of specimens were not improved remarkably through high temperature solid-solution, whereas the mechanical properties of normalized specimens in the three steels were improved to different degrees. The coalescence and sparse distribution of smaller precipitates at grain boundaries after normalizing effectively weakened the local stress concentration arising from the reticular distribution of particles. The normalized specimen of steel A with 0.24 wt% Nb still showed good mechanical properties. Normalizing at 850 °C for 2 h is the appropriate heat treatment for the 18 wt% Cr ferritic stainless steel. The comparatively rational Nb content of the ferritic stainless steel is between 0.20 and 0.40 wt% for investment casting production.

  18. Directionally Solidified Multifunctional Ceramics

    Science.gov (United States)

    2006-12-01

    Vidrio , Vol. 44 [5] (2005) pp 347 - 352. 9. F. W. Dynys and A. Sayir, "Self Assemble Silicide Architectures by Directional Solidification," Journal...Sociedad Espanola de Ceramica y Vidrio , Vol. 43 [4] (2004) pp 753 - 758. 21. A. Sayir and F. S. Lowery, "Combustion-Resistance of Silicon-Based Ceramics...Espafiola de Cerdmica y Vidrio , Vol. 43 [3], 2004. ISSN-0366-3175-BSCVB9. 14 37. P. Berger, A. Sayir and M. H. Berger, "Nuclear Microprobe using Elastic

  19. Effect of Al substitution for Ga on the mechanical properties of directional solidified Fe-Ga alloys

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yangyang; Li, Jiheng; Gao, Xuexu, E-mail: gaox@skl.ustb.edu.cn

    2017-02-01

    Alloys of Fe{sub 82}Ga{sub 18−x}Al{sub x} (x=0, 4.5, 6, 9, 12, 13.5) were prepared by directional solidification technique and exhibited a <001> preferred orientation along the axis of alloy rods. The saturation magnetostriction value of the Fe{sub 82}Ga{sub 13.5}Al{sub 4.5} alloy was 247 ppm under no pre-stress. The tensile properties of alloys of Fe{sub 82}Ga{sub 18−x}Al{sub x} at room temperature were investigated. The results showed that tensile ductility of binary Fe-Ga alloy was significantly improved with Al addition. The fracture elongation of the Fe{sub 82}Ga{sub 18} alloy was only 1.3%, while that of the Fe{sub 82}Ga{sub 9}Al{sub 9} alloy increased up to 16.5%. Addition of Al increased the strength of grain boundary and cleavage, resulting in the enhancement of tensile ductility of the Fe-Ga-Al alloys. Analysis of deformation microstructure showed that a great number of deformation twins formed in the Fe-Ga-Al alloys, which were thought to be the source of serrated yielding in the stress-strain curves. The effect of Al content in the Fe-Ga-Al alloys on tensile ductility was also studied by the analysis of deformation twins. It indicated that the joint effect of slip and twinning was beneficial to obtain the best ductility in the Fe{sub 82}Ga{sub 9}Al{sub 9} alloy. - Highlights: • Tensile ductility of directional solidified Fe-Ga alloys was significantly improved with Al addition. • The fracture elongation of binary Fe{sub 82}Ga{sub 18} alloy was only 1.3% at room temperature. • The fracture elongation of Fe{sub 82}Ga{sub 9}Al{sub 9} alloy was 16.5% at room temperature. • A great number of deformation twins formed in the Fe-Ga-Al alloys during tensile tests at room temperature.

  20. The potential of solidified molasses-based blocks for the correction of multinutritional deficiencies in buffaloes and other ruminants fed low-quality agro-industrial byproducts

    International Nuclear Information System (INIS)

    Leng, R.A.

    1984-01-01

    The main principles for formulating diets for ruminant animals in developing countries are outlined and examples provided of the successful application of these principles for feeding buffaloes and cattle in India, Philippines and Australia. It is concluded that the provision of a continuous supply of urea in the form of solidified feed blocks to increase the intake and digestibility of roughage-based diets is a management tool that could be used by small farmers in developing countries to improve weight gains and milk yields. Since such blocks can be easily supplemented with macro- and micro-elements needed by ruminants, they could also be useful for correcting multi-nutritional deficiencies. (author)

  1. Large magnetoresistance in a directionally solidified Ni44.5Co5.1Mn37.1In13.3 magnetic shape memory alloy

    Science.gov (United States)

    Li, Zongbin; Hu, Wei; Chen, Fenghua; Zhang, Mingang; Li, Zhenzhuang; Yang, Bo; Zhao, Xiang; Zuo, Liang

    2018-04-01

    Polycrystalline Ni44.5Co5.1Mn37.1In13.3 alloy with coarse columnar-shaped grains and 〈0 0 1〉A preferred orientation was prepared by directional solidification. Due to the strong magnetostructural coupling, inverse martensitic transformation can be induced by the magnetic field, resulting in large negative magnetoresistance up to -58% under the field of 3 T. Such significant field controlled functional behaviors should be attributed to the coarse grains and strong preferred orientation in the directionally solidified alloy.

  2. Removal of radioactive cesium from surface soils solidified using polyion complex. Rapid communication for decontamination test at Iitate-mura in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Naganawa, Hirochika; Yanase, Nobuyuki; Mitamura, Hisayoshi; Nagano, Tetsushi; Yoshida, Zenko; Kumazawa, Noriyuki; Saitoh, Hiroshi; Kashima, Kaoru; Fukuda, Tatsuya; Tanaka, Shun-ichi

    2011-01-01

    We tried the decontamination of surface soils for three types of agricultural land at Nagadoro district of Iitate-mura (village) in Fukushima Prefecture, which is highly contaminated by deposits of radionuclides from the plume released from the Fukushima Daiichi nuclear power plant. The decontamination method consisted of the peeling of surface soils solidified using a polyion complex, which was formed from a salt solution of polycations and polyanions. Two types of polyion complex solution were applied to an upland field in a plastic greenhouse, a pasture, and a paddy field. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils. (author)

  3. Determination of performance criteria for high-level solidified nuclear waste from the commercial nuclear fuel cycle: a probabilistic safety analysis

    International Nuclear Information System (INIS)

    Heckman, R.A.

    1978-01-01

    To minimize the radiological risk from the operation of a waste management system for the safe disposal of high-level waste, performance characteristics of the solidified waste form must be specified. The minimum waste form characteristics that must be specified are the radionuclide volatilization fraction, airborne particulate dispersion fraction, and the aqueous dissolution characteristics. The results indicate that the pre-emplacement environs are more limiting in establishing the waste form performance criteria than the post-emplacement environs. The actual values of expected risk are sensitive to modeling assumptions and data base uncertainties. The transportation step appears to be the most limiting in determining the required performance characteristics

  4. An Abnormal Increase of Fatigue Life with Dwell Time during Creep-Fatigue Deformation for Directionally Solidified Ni-Based Superalloy DZ445

    Science.gov (United States)

    Ding, Biao; Ren, Weili; Deng, Kang; Li, Haitao; Liang, Yongchun

    2018-03-01

    The paper investigated the creep-fatigue behavior for directionally solidified nickel-based superalloy DZ445 at 900 °C. It is found that the fatigue life shows an abnormal increase when the dwell time exceeds a critical value during creep-fatigue deformation. The area of hysteresis loop and fractograph explain the phenomenon quite well. The shortest life corresponds to the maximal area of hysteresis loop, i. e. the maximum energy to be consumed during the creep-fatigue cycle. The fractographic observation of failed samples further supports the abnormal behavior of fatigue life.

  5. Influence of Macro-Topography on Damage Tolerance and Fracture Toughness of 0.1 wt % Multi-Layer Graphene/Clay-Epoxy Nanocomposites

    Directory of Open Access Journals (Sweden)

    Rasheed Atif

    2016-07-01

    Full Text Available Influence of topographical features on mechanical properties of 0.1 wt % Multi-Layer Graphene (MLG/clay-epoxy nanocomposites has been studied. Three different compositions were made: (1 0.1 wt % MLG-EP; (2 0.1 wt % clay-EP and (3 0.05 wt % MLG-0.05 wt % clay-EP. The objective of making hybrid nanocomposites was to determine whether synergistic effects are prominent at low weight fraction of 0.1 wt % causing an improvement in mechanical properties. The topographical features studied include waviness (Wa, roughness average (Ra, root mean square value (Rq and maximum roughness height (Rmax or Rz. The Rz of as-cast 0.1 wt % MLG-EP, clay-EP and 0.05 wt % MLG-0.05 wt % clay-EP nanocomposites were 43.52, 48.43 and 41.8 µm respectively. A decrease in Rz values was observed by treating the samples with velvet cloth and abrasive paper 1200P while increased by treating with abrasive papers 320P and 60P. A weight loss of up to 16% was observed in samples after the treatment with the abrasive papers. It was observed that MLG is more effective in improving the mechanical properties of epoxy than nanoclay. In addition, no significant improvement in mechanical properties was observed in hybrid nanocomposites indicating that 0.1 wt % is not sufficient to generate conspicuous synergistic effects.

  6. The predominant WT1 isoform (+KTS) encodes a DNA-binding protein targeting the planar cell polarity gene Scribble in renal podocytes.

    Science.gov (United States)

    Wells, Julie; Rivera, Miguel N; Kim, Woo Jae; Starbuck, Kristen; Haber, Daniel A

    2010-07-01

    WT1 encodes a tumor suppressor first identified by its inactivation in Wilms' Tumor. Although one WT1 splicing variant encodes a well-characterized zinc finger transcription factor, little is known about the function of the most prevalent WT1 isoform, whose DNA binding domain is disrupted by a three-amino acid (KTS) insertion. Using cells that conditionally express WT1(+KTS), we undertook a genome-wide chromatin immunoprecipitation and cloning analysis to identify candidate WT1(+KTS)-regulated promoters. We identified the planar cell polarity gene Scribble (SCRB) as the first WT1(+KTS) target gene in podocytes of the kidney. WT1 and SCRB expression patterns overlap precisely in developing renal glomeruli of mice, and WT1(+KTS) binds to a 33-nucleotide region within the Scribble promoter in mouse and human cell lines and kidneys. Together, our results support a role for the predominant WT1(+KTS) isoform in transcriptional regulation and suggest a link between the WT1-dependent tumor suppressor pathway and a key component of the planar cell polarity pathway.

  7. The predominant WT1 isoform (+KTS) encodes a DNA binding protein targeting the planar cell polarity gene Scribble in renal podocytes

    Science.gov (United States)

    Wells, Julie; Rivera, Miguel N.; Kim, Woo Jae; Starbuck, Kristen; Haber, Daniel A.

    2010-01-01

    WT1 encodes a tumor suppressor, first identified by its inactivation in Wilms Tumor. While one WT1 splicing variant encodes a well-characterized zinc finger transcription factor, little is known about the function of the most prevalent WT1 isoform, whose DNA binding domain is disrupted by a three amino acid (KTS) insertion. Using cells which conditionally express WT1(+KTS), we undertook a genome-wide chromatin immunoprecipitation and cloning (ChIP-cloning) analysis to identify candidate WT1(+KTS) regulated promoters. We identified the planar cell polarity (PCP) gene Scribble (SCRB) as the first WT1(+KTS) target gene in podocytes of the kidney. WT1 and SCRB expression patterns overlap precisely in developing renal glomeruli of mice, and WT1(+KTS) binds to a 33 nucleotide region within the Scribble promoter in both mouse and human cell lines and kidneys. Together, our results support a role for the predominant WT1(+KTS) isoform in transcriptional regulation and suggest a link between the WT1-dependent tumor suppressor pathway and a key component of the planar cell polarity pathway. PMID:20571064

  8. Adsorption and transport of cadmium and rhodamine WT in pumice sand columns

    International Nuclear Information System (INIS)

    Pang, L.; Close, M.; Greenfield, H.; Stanton, G.

    2004-01-01

    The transport and attenuation of cadmium (Cd) and rhodamine WT (RWT) in a pumice sand aquifer media was investigated using column experiments to study a scenario of point-source contamination. A pore-water velocity of 1.7-1.8 m/day, which is a typical field groundwater velocity in a pumice sand aquifer system, was applied to triplicate columns. A pulse of a solution containing Cd and RWT, together with the conservative tracer tritiated water ( 3 H 2 O) at pH = 7, was introduced into the columns. Experimental results showed that concentration breakthrough curves (BTCs) of 3 H 2 O were symmetrical and fitted well into an equilibrium model. In contrast, BTCs of Cd and RWT were asymmetrical with significant tailings and fitted well with a two-site adsorption/desorption model. The symmetric 3 H 2 O BTCs suggest that physical non-equilibrium was absent in the experimental system, therefore the asymmetrical BTCs of Cd and RWT were attributed to chemical non-equilibrium. Modelling results showed that, in comparison with 3 H 2 O, Cd was apparently retarded by 101-108 times in pumice sand aquifer media (apparent adsorption coefficient 7.33-9.24 ml/g) and underwent a mass loss of 20-30% that was probably because of precipitation of CdCO 3 . As CdCO 3 is extremely insoluble, Cd precipitation would be irreversible and therefore it would not contribute to the tailing of the Cd BTCs. The experimental results suggest that the adsorption and desorption of Cd in pumice sand aquifer media in hydrodynamic conditions was a kinetic process. Cd desorption rates were two orders-of-magnitude slower than its adsorption rates. This resulted in a prolonged mean residence time for Cd in pumice sand aquifer media, which was 10-12 days in the 18-cm-long columns under a flow velocity of 1.7-1.8 m/day. Since the mean residence time is only indicative for the arrival of the central of mass in a contaminant BTC, the time required for the total disappearance of Cd will be much longer than the mean

  9. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    Energy Technology Data Exchange (ETDEWEB)

    Karakoese, Ercan [Erciyes University, Institute of Science and Technology, Department of Physics, 38039 Kayseri (Turkey); Keskin, Mustafa, E-mail: keskin@erciyes.edu.tr [Erciyes University, Faculty of Arts and Sciences, Department of Physics, 38039 Kayseri (Turkey)

    2009-12-15

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were {alpha}-Al, intermetallic Al{sub 3}Ni and Al{sub 2}Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al{sub 3}Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  10. Morphological characteristic of the conventional and melt-spun Al-10Ni-5.6Cu (in wt.%) alloy

    International Nuclear Information System (INIS)

    Karakoese, Ercan; Keskin, Mustafa

    2009-01-01

    The Al-10Ni-5.6Cu alloy was prepared by conventional casting and further processed melt-spinning technique. The resulting conventional cast and melt-spun ribbons were characterized using X-ray diffraction, optical microscopy, scanning electron microscopy together with energy dispersive spectroscopy, differential scanning calorimetry and microhardness techniques. The X-ray diffraction analysis indicated that ingot samples were α-Al, intermetallic Al 3 Ni and Al 2 Cu phases. The optical microscopy and scanning electron microscopy results show that the microstructures of rapidly solidified ribbons are clearly different from their ingot alloy. Al-10Ni-5.6Cu ribbons reveal a very fine cellular structure with intermetallic Al 3 Ni particles. Moreover, at high solidification rates the melt-spun ribbons have a polygonal structure dispersed in a supersaturated aluminum matrix. The differential scanning calorimetry measurements revealed that exothermic reaction was between 290 deg. C and 440 deg. C which are more pronounced in the ternary Al-10Ni-5.6Cu alloy.

  11. Effects of strontium on microstructure and mechanical properties of as-cast Mg-5 wt.%Sn alloy

    International Nuclear Information System (INIS)

    Liu, Hongmei; Chen, Yungui; Zhao, Haofeng; Wei, Shanghai; Gao, Wei

    2010-01-01

    The strontium (Sr) addition to the Mg-5 wt.%Sn alloy results in grain refinement and the formation of a rod-shaped and a bone-shaped MgSnSr intermetallic phase which are mainly straddle on the grain boundaries. The yield strength is improved, while the tensile strength and elongation first increased, and then decreased with a large addition of Sr. Optimum mechanical properties at ambient temperature are obtained at a content of 2.14 wt.%Sr. Tensile properties of the alloys at elevated temperatures are also improved, and the decrease of strength at elevated temperature slowed down with increasing Sr addition, indicating that Sr can improve the thermal stability of Mg-Sn alloys.

  12. Effect of graphenenano-platelets on the mechanical properties of Mg/3wt%Al alloy-nanocomposite

    Science.gov (United States)

    Kumar, Pravir; Kujur, MilliSuchita; Mallick, Ashis; Sandar Tun, Khin; Gupta, Manoj

    2018-04-01

    The bulk Mg/3%Al/0.1%GNP alloy-nano composite was fabricated using powder metallurgy route assisted with microwave sintering and followed by hot extrusion. The microstructural and Raman spectroscopy studies were performed to characterize the graphene nano-platelet(GNP).EDX tests confirmed the presence and the homogeneous distribution of Al and graphene nano-platelets in the magnesium alloy-nanocomposite. The addition of 3 wt% Al and 0.1wt%GNP to the Mg changed Vicker hardness, ultimate tensile strength and failure strain by +46.15%,+17.6% and -5% respectively. The fabricated composite offers higher resistance to the local deformation than monolithic Mg and Mg/3%Al alloy, revealed by the load/unload-indentation depth curve.

  13. Phase formation kinetics, hardness and magnetocaloric effect of sub-rapidly solidified LaFe11.6Si1.4 plates during isothermal annealing

    Science.gov (United States)

    Dai, Yuting; Xu, Zhishuai; Luo, Zhiping; Han, Ke; Zhai, Qijie; Zheng, Hongxing

    2018-05-01

    High-temperature phase transition behavior and intrinsic brittleness of NaZn13-type τ1 phase in La-Fe-Si magnetocaloric materials are two key problems from the viewpoint of materials production and practical applications. In the present work, the Johnson-Mehl-Avrami-Kolmogorov (JMAK) equation was introduced to quantitatively characterize the formation kinetics of τ1 phase in sub-rapidly solidified LaFe11.6Si1.4 plates during the isothermal annealing process. Avrami index was estimated to be 0.43 (∼0.5), which suggests that the formation of τ1 phase is in a diffusion-controlled one-dimensional growth mode. Meanwhile, it is found that the Vickers hardness as a function of annealing time for sub-rapidly solidified plates also agrees well with the JMAK equation. The Vickers hardness of τ1 phase was estimated to be about 754. Under a magnetic field change of 30 kOe, the maximum magnetic entropy change was about 22.31 J/(kg·K) for plates annealed at 1323 K for 48 h, and the effective magnetic refrigeration capacity reached 191 J/kg.

  14. Formation of an 18R long-period stacking ordered structure in rapidly solidified Mg88Y8Zn4 alloy

    International Nuclear Information System (INIS)

    Garcés, Gerardo; Requena, Guillermo; Tolnai, Domonkos; Pérez, Pablo; Medina, Judit; Stark, Andreas; Schell, Norbert; Adeva, Paloma

    2016-01-01

    The formation of the long-period stacking ordered structure (LPSO) in a Mg 88 Y 8 Zn 4 (at%) ribbon produced by melt spinning was studied using high energy X-ray synchrotron radiation diffraction during in-situ isochronal heating and transmission electron microscopy. The microstructure of the rapidly solidified ribbons is characterised by fine magnesium grains with yttrium and zinc in solid solution and primary 18R LPSO-phase segregated at grain boundaries. Using differential scanning calorimetry, a strong exothermal peak was observed around 300 °C which was associated with the development of the 18R-type LPSO-phase in the magnesium grains. The apparent activation energy calculated using the Kissinger model was 125 KJmol −1 and it is related to simultaneous diffusion of Y and Zn through magnesium basal plane. - Highlights: •The formation of the LPSO phase in rapidly solidified ribbons was studied. •The formation of the 18R LPSO starts at around 300 °C. •LPSO formation have to steps: Stacking faults along basal plane and then growth of 18R structure along the c direction.

  15. Numerical Research on Magnetic Field, Temperature Field and Flow Field During Melting and Directionally Solidifying TiAl Alloys by Electromagnetic Cold Crucible

    Science.gov (United States)

    Chen, Ruirun; Yang, Yaohua; Gong, Xue; Guo, Jingjie; Su, Yanqing; Ding, Hongsheng; Fu, Hengzhi

    2017-12-01

    The electromagnetic cold crucible (EMCC) technique is an effective method to melt and directionally solidify reactive and high-temperature materials without contamination. The temperature field and fluid flow induced by the electromagnetic field are very important for melting and controlling the microstructure. In this article, a 3D EMCC model for calculating the magnetic field in the charges (TiAl alloys) using the T-Ω finite element method was established and verified. Magnetic fields in the charge under different electrical parameters, positions and dimensions of the charge were calculated and analyzed. The calculated results show that the magnetic field concentrates in the skin layer, and the magnetic flux density ( B) increases with increasing of the frequency, charge diameter and current. The maximum B in the charge is affected by the position of the charge in EMCC ( h 1) and the charge height ( h 2), which emerges at the middle of coils ( h c) when the relationship of h c < h 1 + h 2 < h c + δ is satisfied. Lower frequency and smaller charge diameter can improve the uniformity of the magnetic field in the charge. Consequently, the induced uniform electromagnetic stirring weakens the turbulence and improves temperature uniformity in the vicinity of the solid/liquid (S/L) interface, which is beneficial to forming a planar S/L interface during directional solidification. Based on the above conclusions, the TiAlNb alloy was successfully melted with lower power consumption and directionally solidified by the square EMCC.

  16. NWTS program criteria for mined geologic disposal of nuclear waste: functional requirements and performance criteria for waste packages for solidified high-level waste and spent fuel

    International Nuclear Information System (INIS)

    1982-07-01

    The Department of Energy (DOE) has primary federal responsibility for the development and implementation of safe and environmentally acceptable nuclear waste disposal methods. Currently, the principal emphasis in the program is on emplacement of nuclear wastes in mined geologic repositories well beneath the earth's surface. A brief description of the mined geologic disposal system is provided. The National Waste Terminal Storage (NWTS) program was established under DOE's predecessor, the Energy Research and Development Administration, to provide facilities for the mined geologic disposal of radioactive wastes. The NWTS program includes both the development and the implementation of the technology necessary for designing, constructing, licensing, and operating repositories. The program does not include the management of processing radioactive wastes or of transporting the wastes to repositories. The NWTS-33 series, of which this document is a part, provides guidance for the NWTS program in the development and implementation of licensed mined geologic disposal systems for solidified high-level and transuranic (TRU) wastes. This document presents the functional requirements and performance criteria for waste packages for solidified high-level waste and spent fuel. A separate document to be developed, NWTS-33(4b), will present the requirements and criteria for waste packages for TRU wastes. The hierarchy and application of these requirements and criteria are discussed in Section 2.2

  17. Effect of pH on the release of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resins collected from operating nuclear power stations

    International Nuclear Information System (INIS)

    McIsaac, C.V.; Akers, D.W.; McConnell, J.W.

    1991-06-01

    Data are presented on the physical stability and leachability of radionuclides and chelating agents from cement-solidified decontamination ion-exchange resin wastes collected from two operating commercial light water reactors. Small-scale waste--form specimens collected during solidifications performed at the Brunswick Steam Electric Plant Unit 1 and at the James A. FitzPatrick Nuclear Power Station were leach-tested and subjected to compressive strength testing in accordance with the Nuclear Regulatory Commission's ''Technical Position on Waste Form'' (Revision 1). Samples of untreated resin waste collected from each solidification vessel before the solidification process were analyzed for concentrations of radionuclides, selected transition metals, and chelating agents to determine the quantities of these chemicals in the waste-form specimens. The chelating agents included oxalic, citric, and picolinic acids. In order to determine the effect of leachant chemical composition and pH on the stability and leachability of the waste forms, waste-form specimens were leached in various leachants. Results of this study indicate that differences in pH do not affect releases from cement-solidified decontamination ion-exchange resin waste forms, but that differences in leachant chemistry and the presence of chelating agents may affect the releases of radionuclides and chelating agents. Also, this study indicates that the cumulative releases of radionuclides and chelating agents are similar for waste- form specimens that decomposed and those that retained their general physical form. 36 refs., 60 figs., 28 tabs

  18. Absorption of dissolved hydrogen from lithiated water during accelerated corrosion of zirconium-2.5 wt% niobium alloy

    International Nuclear Information System (INIS)

    Manolescu, A.V.; Mayer, P.; Rasile, E.M.; Mummenhoff, J.W.

    1982-01-01

    A series of laboratory experiments was carried out to determine the extent of dissolved hydrogen absorption from lithiated water by zirconium-2.5 wt% niobium alloy during corrosion. The material was exposed at 340 0 C to 1 M LiOH aqueous solution containing 0 to approximately 70 cm 3 /L of dissolved hydrogen. Results indicate that dissolved hydrogen has no effect on the corrosion rate or on the amount of hydrogen absorbed by the material

  19. Effect of nano size 3% wt TaC particles dispersion in two different metallic matrix composites

    International Nuclear Information System (INIS)

    Gomes, U.U.; Oliveira, L.A.; Souza, C.P.; Menezes, R.C.; Furukava, M.; Torres, Y.

    2009-01-01

    This work studies the characteristics of two different metallic matrixes composites, ferritic and austenitic steels, reinforced with 3% wt nano size tantalum carbide by powder metallurgy. The starting powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effects of the nano sized carbide dispersion on the matrix microstructures and its consequences on the mechanical properties were identified. The preliminary results showed that the sintering were influenced by morphology and the distribution of carbide and the alloys. (author)

  20. The mechanical properties of magnesium matrix composites reinforced with 10 wt.% W14Al86 alloy particles

    International Nuclear Information System (INIS)

    Tang, H.G.; Ma, X.F.; Zhao, W.; Cai, S.G.; Zhao, B.; Qiao, Z.H.

    2007-01-01

    The Mg-based metal matrix composite reinforced by 10 wt.% W 14 Al 86 alloy particles has been prepared by mechanical alloying and press-forming process. X-ray diffraction studies confirm the formation of the composite. Microstructure characterization of the samples reveals the uniform distribution of fine W 14 Al 86 alloy. Mechanical properties characterization revealed that the reinforcement of W 14 Al 86 alloy lead to a significant increase in hardness and tensile strength of Mg and AZ91